CHAPTER XIV.

OF POISONING WITH MERCURY.

The next genus of the metallic poisons includes the preparations of mercury. Some of these are hardly less important than the arsenical compounds. They act with equal energy, produce the same violent symptoms, and cause death with the same rapidity. They have therefore been often given with a criminal intent; and have thus become the subject of inquiry upon trials. In another respect, too, they claim the regard of the medical jurist: their effects on the body, when insidiously introduced in the practice of the arts in which mercury is used, form a branch of that department of medical police, which treats of the influence of trades on the health.

SECTION I.—_Of the Chemical History and Tests for the preparations of Mercury._

Mercury is a fluid metal, exceedingly brilliant, of a silver-white colour, and of the specific gravity 13·568.

When heated to about 660° F. it sublimes, and on cooling it condenses unchanged. If this experiment is made in a small glass tube, the metal forms a white ring of brilliant globules, which may be made to coalesce into a single large one. In this way its physical properties may be recognised, though the quantity is exceedingly minute.

Two oxides of this metal, a protoxide and peroxide, exist in combination with acids. A bluish-gray or grayish-black protoxide is separated from the salts of the protoxide by the fixed alkalis. The peroxide has an orange-red colour, and is the common red precipitate of the apothecary. Mercury unites with sulphur in two proportions. The proto-sulphuret, which is black, is formed from the salts of the protoxide by the action of sulphuretted-hydrogen: the bisulphuret is the well known pigment, cinnabar or vermilion. Mercury likewise unites with chlorine in two proportions, forming an insoluble protochloride and a soluble bichloride, the former calomel, the latter corrosive sublimate. It likewise unites with cyanogen. Mercury also unites in the state of protoxide and peroxide with the acids. Several compound salts are known to the chemist, but few occur in commerce or the arts.

Among the compounds resulting from the action of this metal with other substances, those which require notice in a toxicological treatise are the following:—1. The binoxide or _red precipitate_; 2. The bisulphuret or _vermilion_; 3. The protochloride or _calomel_; 4. The bichloride or _corrosive sublimate_; 5. The sulphate or _Turbith mineral_; 6. The _bicyanide_ or prussiate of mercury; and 7. The _nitrates_ of mercury. Its other compounds are of little consequence to the toxicologist.

1. _Of Red Precipitate._

Red precipitate, when well prepared, is in the form of fine powder or small, brilliant, heavy scales of a scarlet or orange colour. It consists of 101 mercury and 8 oxygen. It is insoluble in water.

It is easily distinguished from all other substances by the action of heat. If a little of it is heated in a small glass tube, it becomes dark brown, and on cooling recovers its original colour. But if the heat be raised higher, metallic globules are sublimed, and oxygen gas is disengaged. The escape of oxygen may be ascertained by plunging to the bottom a small bit of burning wood, when the combustion will be observed to be enlivened.

2. _Of Cinnabar._

Cinnabar or vermilion, the bisulphuret of mercury, usually exists in the arts in the form of a fine, heavy, red powder, of a peculiar tint, which is termed from this substance vermilion-red. In mass its structure is coarsely-fibrous, and its colour reddish-brown; and it has some lustre. When thrown down from a solution of corrosive sublimate by sulphuretted-hydrogen, or the alkaline hydrosulphates, it forms a black powder, which acquires a red tint by being sublimed. It is composed of 101 metal and 16 sulphur.

It is distinguished from other substances by the operation of heat, and by the effects of reduction with iron filings. Heated alone in a tube it sublimes without change. Its colour, indeed, which is fugacious under heat unless particular manipulations are used, becomes darker and dingy; but its lustre and crystalline texture are retained. Heated with iron filings in a tube, it gives off globules of mercury; and the existence of sulphuret of iron in what remains may be proved by the escape of sulphuretted-hydrogen on the addition of diluted sulphuric acid.

3. _Of Turbith Mineral._

The Turbith mineral, or subsulphate of the binoxide of mercury, exists in the form of a bright lemon-yellow, heavy powder. It is soluble in 2000 parts of water, and has an acrid taste.

It may be known by the effects of heat. When heated in a tube, globules of mercury are sublimed, and at the same time sulphurous acid gas is disengaged, as may be ascertained by the smell. But a better method of proving the existence of sulphuric acid in it is to expose it to the action of a solution of caustic potass: The potass separates from it the brownish-yellow peroxide, and appropriates the sulphuric acid, which may be found in the solution by acidulating with nitric acid, and then adding hydrochlorate of baryta, when a heavy, snow-white precipitate of sulphate of baryta will form. The nitric acid used in this process must be quite pure, and free of sulphuric acid, which the acid of commerce often contains.

4. _Of Calomel._

Calomel (muriate, mild muriate, chloride, protochloride of mercury), is commonly met with in the shops in the form of a heavy powder, having a faint yellowish-white colour, and no taste or smell. In mass it forms compact, fibrous, translucent, shining cakes of great density. It is insoluble in water.

It is distinguished by the effects of heat, and those of the solution of caustic potass. Heated in a tube it sublimes unchanged, and condenses in a crystalline or crumbly mass. The solution of caustic potass or soda turns it at once black, disengaging protoxide of mercury and acquiring hydrochloric acid, the presence of which is proved by neutralizing the solution with nitric acid, and adding nitrate of silver, when a heavy white precipitate is formed, the chloride of silver. In applying this process, care must be taken to employ potass quite free of muriates, and nitric acid free of muriatic acid. Ammonia also renders calomel powder black, but the action and product are much more complex in their nature.

5. _Of Corrosive Sublimate._

Corrosive sublimate (oxymuriate, corrosive muriate, bichloride of mercury), is by far the most important of the mercurial poisons, as it is both the most active of them, and the one most frequently used for criminal purposes. It is commonly met with in the form of a heavy, snow-white powder, or of small, broken crystals, or in white, compact, concave, crystalline cakes. It is permanent in the air; but in the sunshine is slowly decomposed, a gray insoluble powder being formed. It readily crystallizes, and the common form of the crystals is the quadrangular prism. Its specific gravity is 5·2. Its taste is strongly styptic, metallic, acrid, and persistent; and its dust powerfully irritates the nostrils. It is soluble, according to Thenard, in 20, according to Orfila, in 11 parts of temperate water, and in thrice its weight of boiling water. Its solution faintly reddens litmus. It is more soluble in alcohol than in water, boiling alcohol dissolving its own weight, and retaining when it cools, a fourth part. It is also very soluble in ether, so that ether will remove it from its aqueous solution. Corrosive sublimate may become the subject of a medico-legal analysis in three states. It may be in the solid form; it may be dissolved in water along with other mineral substances; and it may be mixed with vegetable and animal fluids or solids.

_Of the Tests for Corrosive Sublimate in the solid state._

Corrosive sublimate in the solid state is distinguished from other substances by the action of the heat, and the effects of solution of caustic potass. Subjected to heat alone it sublimes in white acrid fumes; and if the experiment is made in a little tube, it condenses again unaltered in a crystalline cake. Treated with solution of caustic potass, it becomes yellow, the binoxide being disengaged, and hydrochloric acid uniting with the potass, as may be proved by nitrate of silver, after filtration and neutralization with nitric acid. The yellow colour of the binoxide which is separated in this process distinguishes corrosive sublimate from calomel, which is also decomposed by the potass solution, but yields a black protoxide. Caustic soda has the same effect. Not so caustic ammonia: Ammonia blackens calomel, but does not change the colour of corrosive sublimate, as it forms with it a white triple salt, commonly called white precipitate.

The process here described is the best and simplest method of determining chemically the nature of corrosive sublimate in its solid state. But two other tests may also be mentioned, as they have been a good deal used. A very good test is the process of reduction with potass, by which globules of mercury are sublimed, and a chloride of potassium left in the flux, as may be proved by the action of nitrate of silver on the solution of the flux previously neutralized with nitric acid. This test alone will not distinguish corrosive sublimate from calomel: The solubility of the former must be taken into account.—Another satisfactory test is the solution of protochloride of tin. Corrosive sublimate, when left for some time in this solution, first becomes grayish-black, and ere long its place is supplied by globules of mercury,—the chlorine being entirely abstracted by the protochloride of tin, which consequently passes to the state of a bichloride. Calomel is similarly affected.

_Of the Tests for Corrosive Sublimate in a state of Solution._

Two processes may be mentioned for the detection of corrosive sublimate in mineral solutions,—a process by reduction, and a process by liquid tests.

_Reduction process._—In order to procure mercury in its characteristic metallic state from a solution of corrosive sublimate, the following plan of procedure will be found the most delicate and convenient. Add to the solution, previously acidulated with hydrochloric acid if very weak, a little of the protochloride of tin, which will be seen presently to be a liquid reagent of great delicacy. If the solution is not darkened there is not present an appreciable quantity of mercury. If mercury is present a bluish-gray or grayish-black precipitate falls down, owing to the chemical action already particularized. After ebullition, this precipitate is to be allowed to subside, first in a tall glass vessel suited to the quantity of the solution, and afterwards in the small glass tube, Fig. 7, the superincumbent fluid being previously decanted off as far as possible. After it has subsided in the tube, the remaining fluid is withdrawn with the pipette, Fig. 8; water is poured over it; and this is withdrawn again after the precipitate has subsided a third time. The bottom of the tube is then cut off with a file, and the moisture which remains is driven off with a gentle heat. When this is accomplished, the powder, which is nothing else than metallic mercury, sometimes runs into globules. Should it not do so, the bit of tube is to be broken in pieces and heated in the tube, Fig. 1, when a brilliant ring of fine globules will be formed. If the globules are too minute to be visible to the naked eye, the tube is to be cut off with the file close to the ring; and the globules may then be easily made to coalesce into one or more of visible magnitude by scraping the inside of the tube with the point of a penknife.

This process is not recommended as preferable to the plan by liquid reagents which is next to be mentioned, and which is both more easily put in practice, and at the same time quite as satisfactory. It is related chiefly because it forms the ground-work of a process for detecting mercury in mixed animal or vegetable fluids. It will be remarked that the process does not prove with what acid the mercury was combined in the solution. But this is a defect of little consequence; for the only other soluble salts of mercury ever met with in the arts, namely, the nitrate, acetate, and cyanide, are too rare to be the source of any material fallacy; and are besides all equally poisonous with corrosive sublimate.

_Process by Liquid Tests._—The process by liquid reagents consists in the application of several tests to separate portions of the solution. The tests which appear to me the most satisfactory are hydrosulphuric acid gas, hydriodate of potass, protochloride of tin, and nitrate of silver.

1. _Hydrosulphuric acid gas_ transmitted in a stream through a solution of corrosive sublimate causes a dark, brownish-black precipitate, the bisulphuret of mercury. When the solution is not very diluted, the gas forms a whitish or yellowish precipitate before the blackening commences,—an effect which, according to Pfaff, distinguishes the salts of the peroxide of mercury from all other metals that are thrown down black from their solutions by sulphuretted-hydrogen.[835] The cause of this is that the particles of sulphuret first formed acquire a thin covering of corrosive sublimate by that property which chemists of late have termed superficial attraction. Hydrosulphuric acid is a very delicate test of the presence of mercury. It will detect corrosive sublimate, where its proportion is only a 35000th of the solution.[836]

This test is not alone sufficient, unless reliance be placed on Pfaff’s criterion, which is rather a trivial one; for hydrosulphuric acid occasions a black precipitate in other metallic solutions, for example, in solutions of lead, copper, bismuth and silver. In mixed organic fluids its action is not liable to be prevented; but the precipitate formed is often kept intimately suspended, as in the instance of milk. It may be conveniently used in the form of hydrosulphate of ammonia. This test produces a dark-brown precipitate, which is said to pass slowly to a bright cinnabar red; but I have not been able to observe any transformation of the kind.

_Hydriodate of Potass_ causes in solutions of corrosive sublimate a beautiful pale scarlet precipitate, which rapidly deepens in tint. The precipitate is the biniodide of mercury. This is a test of great delicacy when skilfully used, as it acts where the salt forms only a 7000th of the solution (Devergie). Care must be taken, however, not to add too much of the test, because the precipitate is soluble in an excess of the hydriodate, or too little, because the precipitate is also soluble in a considerable excess of corrosive sublimate.

The action of hydriodate of potass is not liable to any important ambiguity: no other iodide resembles in colour the biniodide of mercury. It is not a certain test, however, when other salts exist in solution along with corrosive sublimate. Chloride of sodium, nitrate of potass, and probably also other neutral salts possess the power of dissolving the precipitate. Sulphuric and nitric acids, even considerably diluted, oxidate and dissolve the mercury, and disengage iodine, which colours the fluid reddish-brown. When corrosive sublimate is dissolved in coloured vegetable infusions or animal fluids, the hydriodate of potass cannot be relied on, the colour of the precipitate being altered, as in infusion of galls, or the action of the test being suspended altogether, as by milk.

_Protochloride of Tin_ causes first a white precipitate, which, when more of the test is added, gives place to a grayish-black one. In very diluted solutions the colour struck is grayish or grayish-black from the beginning. In such solutions Devergie has found it useful to acidulate with hydrochloric acid before adding the test. The chemical action here is peculiar. The white powder thrown down at first is protochloride of mercury; a part of the chlorine of the bichloride of mercury having been abstracted by the protochloride of tin, which becomes in consequence the bichloride. On more of the test being added these changes are repeated, the chlorine is removed from the protochloride of mercury, and metallic mercury falls down. This test is one of extreme delicacy, affecting solutions which contain only an 80,000th of salt. It is prepared by acting on tin powder or tinfoil with strong hydrochloric acid aided by a gentle heat. The solution must be kept carefully excluded from the air; otherwise bichloride of tin is formed, which does not act at all on the solution of corrosive sublimate.

The protochloride of tin is not liable to any fallacy. Neither is it liable to be suspended in its action by the co-existence of other saline substances. It causes precipitates with almost all animal and most vegetable fluids. But when corrosive sublimate is present, even in very small proportion, the precipitate is always darker than when no mercurial salt exists in solution, and frequently has its proper grayish-black tint. This property, as will presently be seen, is the foundation of a process for the detection of mercury in all states of admixture with organic matters.

_Nitrate of Silver_ causes a heavy white precipitate, the chloride of silver, which darkens under exposure to light. This is a test for the chlorine of the corrosive sublimate, but not for the mercury, and is a necessary addition to the three former tests in order to determine how the mercury is kept in solution. It acts with very great delicacy.

It is of no use, however, when chlorine or hydrochloric acid is present either free or combined with other bases. It is not of use, therefore, in animal fluids and vegetable infusions, because very many of them, besides organic principles which form white precipitates with this test, contain a sensible proportion of hydrochlorate of soda.

Although the preceding liquid reagents when employed conjunctly are amply sufficient for determining the presence of corrosive sublimate in a fluid, many other tests hardly less characteristic and delicate have been used by medical jurists. These will now be shortly mentioned.

1. _Lime-Water_ throws down the binoxide of mercury in the form of a heavy yellow powder. The precipitate first thrown down is lemon-yellow, an additional quantity of the test gives it a reddish-yellow tint, and a still larger quantity restores the lemon-yellow. This test is characteristic, but not so delicate as those already mentioned.—2. _Caustic Potass_ has precisely the same effect as lime-water, except that the tint of the precipitate is always yellow—3. _Caustic Ammonia_ causes a fine, white, flocculent precipitate of intricate composition, commonly called precipitate. It is a very delicate test; but ammonia likewise causes a white precipitate in other metallic solutions.—4. _Carbonate of Potass_ causes a brisk-red precipitate, by virtue of a double decomposition, the precipitate being carbonate of mercury.—5. The _Ferro-cyanate of Potass_ causes at first a white precipitate, the ferro-cyanide of mercury. The precipitate becomes slowly yellowish, and at length pale-blue, owing, it is believed, to the admixture of a small quantity of iron with the corrosive sublimate.—6. _A polished plate of Copper_ immersed in a solution of corrosive sublimate becomes in a few seconds tarnished and brownish; and in the course of half an hour a grayish-white powder is formed on its surface. This powder, according to Orfila,[837] is a mixture of calomel, mercury, and a copper amalgam. If it is wiped off, and the plate then rubbed briskly where tarnished, it assumes a white argentine appearance.—7. _A little Mercury_ put into a solution of corrosive sublimate is instantly tarnished on the surface; the solution in a few seconds becomes turbid, a heavy grayish precipitate is formed, and in no long time with the aid of agitation the whole corrosive sublimate is removed from the solution. The powdery precipitate is a mixture of finely divided mercury and calomel; the former being derived from the surface of the mercury, and the latter produced by the corrosive sublimate uniting with a larger proportion of the metal to form the protochloride.—8. _A solution of Albumen_ causes a white precipitate, which is soluble in a considerable excess of the reagent. The nature of this precipitate will be discussed presently.—A _slip of Gold_ aided by galvanism, becomes silver-white in the solution, in consequence of the formation of an amalgam. When the solution is concentrated, it may be thus tested by simply putting a few drops on a bit of gold, and touching the gold through the solution with an iron point, as recommended by Mr. Sylvester and Dr. Paris.[838] When the solution is very weak, a different method is necessary, and a process for the purpose has been proposed by M. Devergie, which appears so delicate, accurate, and at the same time simple, a mode of detecting traces of mercury in very weak solutions, as to deserve detailed notice. A thin plate of gold, and another of tin, a few lines broad, and two or three inches long, being closely applied to one another by silk threads at the ends, and then twisted spirally, this galvanic pile is left for twenty-four or thirty-six hours in the solution previously acidulated with muriatic acid; upon which the gold is found whitened, and mercury may be obtained in globules by heating the gold in a tube. Distinct indications may be obtained by this method, where the corrosive sublimate forms but an 80,000th of the water.[839] For facility of application, an important condition is, that the quantity of fluid should not exceed three or four ounces, because in a larger quantity the pile of the size stated above cannot remove the whole mercury. Somewhat similar to this is the galvanic method of Mr. Davy of Dublin. He proposes to place the suspected solution in a platinum crucible with hydrochloric acid, diluted with its own weight of water, to excite galvanic action by immersing in the fluid a plate of zinc, and to sublime and collect the reduced mercury, by washing the crucible, heating it over a spirit-lamp, and condensing the mercurial vapours on a plate of glass placed over the mouth of the crucible.[840]

_Of the Tests for Corrosive Sublimate when mixed with Organic Fluids and Solids._

The process for detecting corrosive sublimate in mixtures of organic fluids and solids, such as the contents of the stomach, is now to be described. But some remarks are previously required on the chemical relations subsisting between this poison and various principles of the vegetable and animal kingdoms.

These relations are important in a medico-legal point of view on several grounds. On the one hand, the chemical changes which corrosive sublimate undergoes often alter so much the action of its tests, as to render necessary a process of analysis materially different from any hitherto described. And on the other hand, these chemical changes, of which some take place rapidly, others slowly, will hinder the corrosive sublimate, more or less completely, from exerting its usual operation on the animal system; so that it may thus either accidentally fail to act as intended, or be checked in its operation by antidotes administered for the purpose.

It appears from the researches of M. Boullay, confirmed by those of Professor Orfila, that various vegetable fluids, extracts, fixed oils, volatile oils and resins, possess the power of decomposing corrosive sublimate. According to M. Boullay, a part of the chlorine is gradually disengaged in the form of hydrochloric acid, and the salt is consequently converted into calomel, which is deposited in a state of mixture or combination with vegetable matter.[841] Some vegetable fluids produce this change at once, others not for some hours, others not for days, and only when aided by a temperature approaching ebullition. For example, a strong infusion of tea, mixed with a solution of a few grains of corrosive sublimate, becomes immediately muddy, and an insoluble cloud separates in half an hour. But the remaining fluid slowly becomes muddy again, and in eight days a considerable precipitate is formed. Both precipitates contain mercury; the former, I find, contains 31 per cent. On the other hand, an infusion of galls in like circumstances does not become muddy for six or seven hours. A solution of sugar does not undergo any change after being mixed with a solution of corrosive sublimate for months at the ordinary temperature of the atmosphere; but at the temperature of ebullition Boullay has found that the usual changes ensue, though to no great extent.

The experiments of Professor Taddei of Florence have farther shown, that the property of decomposing corrosive sublimate is possessed in an eminent degree by one of the vegetable solids, gluten. If the salt in solution is properly mixed with a due proportion of gluten of wheat, that is, about four times its weight, the water will be found no longer to contain any mercury, while the gluten becomes whitish, brittle, hard, and not prone to putrefaction. A ternary compound is formed, the protochloride of mercury and gluten.[842] This change is effected with rapidity.

The researches of Berthollet,[843] repeated and extended by Professor Orfila,[844] have also shown that the same property is possessed by most animal fluids and solids. Among the soluble animal principles, albumen, caesin, osmazôme, and gelatin possess it in a high degree, but above all albumen, the action of which has been examined with some care, as it supplies the physician with the most convenient and effectual antidote against the effects of the poison.

If a solution of albumen, for example that procured by beating white of eggs in water, is dropped by degrees into a solution of corrosive sublimate, a white flaky precipitate is immediately thrown down, which when separated and dried forms horny masses, hard, brittle, and pulverizable. The precipitate is soluble in a considerable excess of albumen; so that wherever albumen abounds in any fluid, to which corrosive sublimate has been added, a portion of the mercury will always be found in solution. The precipitate is also soluble in a considerable excess of corrosive sublimate. The dry precipitate I have found to contain 6 per cent. of metallic mercury.

The action of casein as it exists in milk is precisely the same. A solution of corrosive sublimate, poured into a large quantity of milk, causes no change; but if the proportion of salt be considerable, a flaky coagulum is formed, and the milk becomes clear. The principles, osmazôme and gelatin, are similar in their effects, though not quite so powerful. Urea has no chemical action with corrosive sublimate. Of the compound animal fluids, blood and serum have the same effects as albumen.

Many insoluble animal principles, as well as all the soft solids of the animal body, act in the same manner with vegetable gluten. Fibrin, for example, coagulated albumen, or coagulated casein, acts precisely in the same way. Muscular fibre, the mucous and serous membranes, the fibrous textures, and the brain, have all the same effect: they become firmer, brittle, white, and a white powder detaches itself from their surface, which contains mercury and animal matter. This chemical action, which Taddei has proved to take place in the living[845] as well as in the dead body, is the source of the corrosive property of the poison, as was first pointed out by Berthollet in his essay formerly quoted.

In all of the compounds thus formed by vegetable and animal substances, the presence of mercury is easily proved by boiling the powder in a solution of caustic potass. The organized matter is dissolved; a heavy, grayish-black powder is formed, which is protoxide of mercury; and if this be collected in the way formerly described, it forms running quicksilver when heated.

A difference of opinion prevails as to the nature of the changes effected by the mutual action of corrosive sublimate and organic matter. For example, in the instance of the action of albumen, which has been most carefully examined, Berzelius and Lassaigne[846] regard the precipitate as a compound of bichloride of mercury with albumen. Professor Rose and Dr. Geoghegan[847] have proved it, in their opinion, to be a compound of binoxide of mercury and albumen without any chlorine. And according to Boullay it is composed of albumen in union with calomel.[848] Lassaigne says he has found it to be a compound of ten equivalents of albumen with one of mercury, or 93·33 per cent. of the former, and 6·67 of the latter.[849] The compound with fibrin he considers to be analogous in composition.

With regard to the changes induced by these effects of organized matter on the operation of the liquid tests for corrosive sublimate, it will in the first place be manifest that the poison may thus be wholly removed from their sphere of action: it may be thrown down as an insoluble substance, on which any process by liquid tests hitherto mentioned will of course fail to act. But secondly, even when a moderate quantity does remain in solution, the operation of the liquid tests, as formerly noticed under the head of each, will be materially modified. It is of some moment for the medical jurist to remember, that by reason of the slowness with which the changes in question sometimes takes place, the poison may exist abundantly in solution at one time, and yet be present only in small quantity after an interval of some hours or days.

_Process for Organic Mixtures._—Various processes have been proposed for detecting corrosive sublimate in organic mixtures. The first I shall mention is one proposed by myself in former editions of this work. It is a double one; of which sometimes the first part, sometimes the second, sometimes both may be required. The first removes the corrosive sublimate undecomposed from the mixture, which may be accomplished when its proportion is considerable; the second, when the proportion of corrosive sublimate is too small to admit of being so removed, separates from the mixture metallic mercury; and the analyst will know which of the two to employ by using the protochloride of tin as a trial-test in the following manner.

A fluid mixture being in the first instance made, if necessary, by dividing and bruising all soft solids into very small fragments, and boiling the mass in distilled water, a small portion is to be filtered for the trial. If the protochloride of tin causes a pretty deep ash-gray or grayish-black colour, the first process may prove successful; if the shade acquired is not deep, that process may be neglected, and the second put in practice at once.

_First branch of the Process._—In order to remove the corrosive sublimate undecomposed, the mixture, without filtration, is to be agitated for a few minutes with about a fourth part of its volume of sulphuric ether; which possesses the property of abstracting the salt from its aqueous solution. On remaining at rest for half a minute or a little more, the etherial solution rises to the surface, and may then be removed by suction with the pipette (Fig. 8). It is next to be filtered if requisite, evaporated to dryness, and the residue treated with boiling water; upon which a solution is procured that will present the properties formerly mentioned as belonging to corrosive sublimate in its dissolved state. This branch of the process is derived from one of Orfila’s methods.

_Second branch of the Process._—If the preceding method should fail, or shall have been judged inapplicable, as will very generally be the case, the mixture is to be treated in the following manner. In the first place, all particles of seeds, leaves, and other fibrous matter of a vegetable nature, are to be removed as carefully as possible. This being done, the mixture, without undergoing filtration, is to be treated with protochloride of tin as long as any precipitate or coagulum is formed. If there were solid animal matters in the mixture, besides being cut and carefully bruised as directed above, they should also be brought thoroughly in contact with the salt of tin by trituration. The mixture, even if it contains but a very minute proportion of mercury, will acquire a slate-gray tint, and become easily separable into a liquid and coagulum. The coagulum is to be collected, washed and drained on a filter; from which it is then to be removed without being dried; and care should be taken not to tear away with it any fibres of the paper, as these would obstruct the succeeding operations. The mercury exists in it in the metallic state for reasons formerly mentioned.

The precipitate is next to be boiled in a moderately strong solution of caustic potass contained in a glass flask, or still better in a smooth porcelain vessel glazed with porcelain; and the ebullition is to be continued till all the lumps disappear. The animal and vegetable matter, and oxide of tin united with them, will thus be dissolved; and on the solution being allowed to remain at rest, a heavy grayish-black powder will begin to fall down in a few seconds. This is chiefly metallic mercury, of which, indeed, globules may sometimes be discerned with the naked eye or with a small magnifier.

In order to separate it, leave the solution at rest under a temperature a little short of ebullition for fifteen or twenty minutes, or longer, if necessary. Fill up the vessel gently with hot water without disturbing the precipitate, so that a fatty matter, which rises to the surface in the case of most animal mixtures, may be skimmed off first with a spoon, and afterwards with filtering paper. Then withdraw the whole supernatant fluid, which is easily done on account of the great density of the black powder. Transfer the powder into a small glass tube, and wash it by the process of affusion and subsidence till the washings do not taste alkaline. Any fibrous matter which may have escaped notice at the commencement of the process, and any lumpy matter which may have escaped solution by the potass, should now be picked out. The black powder is the only part which should be preserved. If the quantity of powder is very minute, an interval of twelve hours should be allowed for each subsidence, and the tube represented in Fig. 7 should be used.

Lastly, the powder is to be removed, heated, and sublimed, as in the last stage of the process described in page 293, for detecting corrosive sublimate in a pure solution.

The second branch of this process is very delicate. I have detected by it a quarter of a grain of corrosive sublimate mixed with two ounces of beef, or with five ounces of new milk, or porter, or tea made with a liberal allowance of cream and sugar. I have also detected a tenth part of a grain in four ounces of the last mixture, that is in 19,200 times its weight.

It may be applied successfully and without difficulty to a very large majority of medico-legal cases. The only difficulty in the way of applying it to all organic mixtures whatever arises from the occasional presence of some vegetable matters, such as seeds, leaves, ligneous fibre and the like, which are insoluble in caustic potass, and which may therefore be left behind with the mercurial precipitate, and obstruct the subsequent sublimation of the metal. This difficulty may be sometimes got rid of, as recommended above, by picking such matters out of the mixture before the protochloride of tin is added. No mercury is lost by so doing, for none of it is united with these vegetable matters: corrosive sublimate does not form any chemical compound with them as it does with other vegetable matters soluble in caustic potass, and with the soft animal solids. When the particles are too small to admit of being thus removed, or cannot be afterwards removed during the process of washing the black powder, which is left after the action of potass—the analyst must be content with the increased facility of sublimation derived from the abstraction of other vegetable and animal admixtures, and take care to use a tube of greater length and with a larger ball than usual. If the sublimate is too much obscured by empyreumatized matter to exhibit distinctly its metallic, globular appearance, the portion of the tube is to be broken off, and scraped, washed, and boiled with a little rectified spirit in a tube. If the globules do not then become visible, a second sublimation will render them distinct. This supplemental operation, however, will be very seldom required; and the process given above will be found to apply to a great majority of instances.

Various objections brought against this process by reviewers and others were noticed in previous editions of this work. The result of the investigation is, that, though not by any means a perfect process, it is one of the most convenient and certain, and least fallacious of all yet proposed. The first step for separating corrosive sublimate by ether in the undecomposed state,—which is borrowed from a suggestion of Professor Orfila, will seldom succeed; for the poison is seldom present in sufficient quantity.

It must be observed that this as well as every other method yet proposed for discovering corrosive sublimate in compound mixtures merely indicates the presence of mercury, and does not point out its state of combination. More especially, in the case of the contents of the stomach, if mercury be not obtained from the filtered fluid, it is impossible to know whether what is detected in the solid matter only may not have proceeded from calomel given medicinally. This objection can be obviated solely by sufficient evidence that calomel was not administered; at least the different criterions laid down by Professor Orfila for distinguishing calomel in the alimentary canal from the products of the decomposition of corrosive sublimate do not appear sufficiently precise, or commonly applicable.[850]

Various processes for detecting corrosive sublimate in organic mixtures have been proposed by others. But none of these seem to me preferable to the method detailed above, with the exception of one which has been lately proposed by Professor Orfila, and which is particularly deserving of notice, because, although complex, he has found it sufficiently manageable and delicate for detecting mercury in the animal textures and secretions, into which it has obtained admission through the medium of absorption in cases of poisoning with the compounds of mercury. Like the previous process, however, it merely detects mercury, and cannot point out the state of combination in which mercury was administered, or mixed with the substance examined.

If the suspected matter be sufficiently liquid, boil for a few minutes and filter; acidulate the product with a few drops of hydrochloric acid; and immerse some slips of copper-leaf in it for a few hours. Should they be tarnished, dissolve oxide and chloride of copper from the surface by means of ammonia; wash them and press them between folds of filtering paper; cut them in pieces, and heat these in a glass tube. Globules of mercury may be obtained or not. In either case, let the liquid, in which the plates were first immersed, be evaporated to dryness over the vapour-bath; add to the residue a sixth of sulphuric acid in a retort with a receiver; and heat gently till a nearly dry carbonaceous mass be obtained. Boil this with an ounce and a half of nitro-hydrochloric acid [Edin. Pharm.], until the charcoal be again nearly dry. Heat what remains with boiling distilled water, filter, apply to a small part of the liquid the copper test as just described, and try whether corrosive sublimate can be detached from the remainder by means of sulphuric ether (p. 299). The distilled fluid in the receiver may contain corrosive sublimate in considerable proportion, relatively to what existed in the subject of analysis. In order to discover it, boil the liquid for fifteen minutes with nitro-hydrochloric acid; transmit chlorine gas for an hour, filter, and evaporate to dryness over the vapour-bath; dissolve the residue in water, and search for corrosive sublimate both by copper plates, and by agitation with ether.

If mercury be not thus detected, proceed to the solid matter left on the filter, by which the subject of analysis was in the first instance separated into a liquid and solid part. Examine this by evaporation to dryness over the vapour-bath, and charring with sulphuric acid in a retort with a receiver attached; and then subject the product to the same steps as those detailed above for the dried residuum of the liquid part.

If the materials for analysis be soft solids, especially the stomach, intestines, liver, and the like, commence at once with the process of charring with sulphuric acid. In the case of the urine, examine both the liquid and sediment. Filter the liquid, transmit chlorine to excess, let the product rest twenty-four hours, filter, evaporate to dryness, dissolve the residue in water acidulated with hydrochloric acid, and test the solution both with copper-leaf and by agitation with ether. Heat the sediment with nitro-hydrochloric acid as directed above, and then proceed as with the liquid portion of the urine.[851]

Some other processes, but probably inferior to that of Professor Orfila, will be found in the last edition of this work. It seems unnecessary to reproduce them here.

6. _Of Bicyanide of Mercury._

The bicyanide of mercury is a compound of mercury and cyanogen. It is usually sold in the form of white, opaque, heavy, crystals, which are rhomboidal prisms. It has a disagreeable, corrosive, metallic taste. It is easily known from every other substance by the effects of heat. If a small quantity of it, previously well dried, be introduced into a glass phial to which a small tube is fitted by means of a cork, on the application of heat the salt becomes black; mercury is sublimed, and condenses in globules on the upper part of the phial; and a gas escapes, which has the odour of prussic acid, and burns with a beautiful rose-red flame.

7. _Of the Nitrates of Mercury._

The nitrates of mercury are used in some of the arts, but have so rarely been the cause of injury to man that they are of little medico-legal importance. I am acquainted with only one case of poisoning with them.[852]

There are two nitrates, the protonitrate and pernitrate. 1. The protonitrate is in transparent colourless crystals, entirely soluble in water with the aid of a slight excess of nitric acid; and the solution is precipitated black by the alkalis, black by sulphuretted-hydrogen, white by muriatic acid, and yellow by hydriodate of potass. The crystals when heated discharge fumes of nitrous acid, and when the whole acid is driven off the red oxide is left, which by farther heat is converted into metallic mercury. 2. The pernitrate is similarly affected by heat. Its crystals form white or yellowish needles. Water decomposes them, separating an insoluble yellowish subnitrate, and dissolving a supernitrate, which is precipitated yellow by the alkalis, black by sulphuretted-hydrogen, carmine-red by the hydriodate of potass. Copper separates mercury from both nitrates; and so does gold or platinum when aided by a galvanic current.

SECTION II.—_Of the mode of Action of Mercury and the Symptoms it excites in Man._

The effects of mercury on the animal body are more diversified than those of any other poison. It acts on a great number of important organs, and in consequence the phenomena of its action are proportionately various. It is not surprising, therefore, that some ambiguity still prevails as to its mode of action and the circumstances by which the action is regulated.

The attention of toxicologists in their physiological researches has been chiefly turned to the more active preparations of mercury, and especially to corrosive sublimate, when given in such quantity as to prove fatal in a few days at farthest. The more immediate and prominent properties of corrosive sublimate have consequently received some elucidation. But its qualities as a slow poison, as well as the analogous operation of the less active compounds of mercury, have not been experimentally examined with the same care: indeed it is questionable whether the phenomena of the latter description as they occur in man can be studied with much advantage by means of experiments on animals.—In treating of the mode in which the compounds of mercury act, the most convenient method will be to consider at present its action in the form of corrosive sublimate in large doses as ascertained by late experiments, and to reserve the consideration of the general action of mercurial poisons at large till their effects on man have been fully described.

The mode of action of corrosive sublimate has been examined particularly by Sir B. Brodie in 1812;[853] by Dr. Campbell in 1813,[854] by M. Smith in 1815,[855] by M. Gaspard in 1821,[856] and more lately by Professor Orfila.[857] The following is a short analysis of their experiments and results.

The leading phenomena remarked by Sir B. Brodie, on large doses being introduced into the stomach, were very rapid death, corrosion of the stomach, and paralysis of the heart. In rabbits and cats, from six to twenty grains, injected in a state of solution into the stomach, produced in a few minutes insensibility and laborious breathing, then convulsions, and death immediately afterwards,—the whole duration of the poisoning varying from five to twenty-five minutes. After death the inner membrane of the stomach was gray, brittle, and here and there pulpy,—changes precisely the same with those produced by corrosive sublimate on the dead stomach. When the chest was opened immediately after death, the heart was found either motionless or contracting feebly; and in both circumstances the blood in its left cavities was arterial.

These experiments make it evident that the brain was acted on as well as the heart, and that the immediate cause of death was stoppage of the heart’s action. But they do not show whether the action takes place through absorption, or by a primary nervous impression transmitted along the nerves.

I am not acquainted with any other experiments of consequence on the operation of corrosive sublimate when introduced into the alimentary canal. But some interesting observations have been made by Campbell, Smith, Gaspard, and Orfila severally as to its effects when applied to the cellular tissue or injected at once into the blood of a vein. It follows from their researches, taken along with those of Sir B. Brodie, that, like arsenic, corrosive sublimate is an active poison, to whatever part or tissue in the body it is applied.

Campbell, Smith, and Orfila all agree in assigning to it dangerous properties, when it is applied to a wound or the cellular tissue of animals. Even in the solid state, and in the dose of three, four, or five grains only, it causes death in the course of the second, third, fourth, or fifth day. The symptoms antecedent to death are generally those of dysentery; and corresponding appearances are found after death, namely, redness, blackness, or even ulceration of the villous coat of the stomach and rectum, the intermediate part of the alimentary canal being sound. This poison, therefore, has, like arsenic, the singular power of inflaming the stomach and intestines, even when it is introduced into the system through a wound.

But this is not its only property in such circumstances. According to Smith and Orfila, it also possesses the power of inflaming both the lungs and the heart. Orfila found the lungs unusually compact and œdematous in some parts; and Smith observed on their anterior surface black spots, elevated in the centre, evidently the consequence of effusion of blood. As to the heart, in one of Smith’s experiments black spots were found in its substance, immediately beneath the lining membrane of the ventricles; and Orfila invariably found in one part or another of the lining membrane, most commonly on the valves, little spots of a cherry-red or almost black colour; nay, on one occasion he observed these spots so soft that slight friction made little cavities. The production of pneumonia by corrosive sublimate when applied to a wound appears well established; but the appearances assumed as indications of carditis are equivocal, since they may have arisen simply from dyeing of the membrane of the heart in the fluid part of the blood after death.

The researches of Gaspard were confined to the effects of the poison when injected at once into the blood. They show still more clearly its tendency to cause inflammation of the lungs; and they prove that through the channel of the blood, as through the cellular tissue, it is apt to cause inflammation of the stomach and rectum. The symptoms were vomiting, bloody diarrhœa, difficult breathing, apparent pain of chest, and bloody sputa; and death took place in a few seconds or in three or four days, according to the dose, which varied from one to five grains. The appearances in the dead body were principally redness in the mucous membrane of the intestines; and in the lungs, according to the length of time the animal survived, either black ecchymosed spots, or black tubercular masses, some inflamed, others gangrenous, others suppurated, or finally, regular abscesses separated from one another by healthy pulmonary tissue.[858]

Besides the effects mentioned in the preceding abstract, two of the experimentalists referred to have likewise observed in animals the same remarkable operation on the salivary organs which forms so conspicuous a feature in the action of the compounds of mercury on man. Dr. Campbell observed mercurial fetor, and M. Gaspard mercurial salivation. Another writer, Zeller, found that dogs might be made to salivate, but not graminivorous animals.[859] Schubarth, however, remarked profuse salivation in a horse, to which twenty-four ounces of strong mercurial ointment were administered in the way of friction in sixteen days:[860] and I observed the same symptoms in a rabbit on the sixth day after the commencement of daily mercurial inunction.

The result of the preceding inquiry is, that corrosive sublimate causes, when swallowed, corrosion of the stomach, and in whatever way it obtains entrance into the body, irritation of that organ and of the rectum, inflammation of the lungs, depressed action and perhaps also inflammation of the heart, oppression of the functions of the brain, inflammation of the salivary glands. These phenomena are diversified enough. But it will presently be found that other organs still are implicated in its effects on man.

Before proceeding, however, to its effects on man, some notice may be taken of a question, connected with its mode of action, which has long been the subject of controversy. The experiments already quoted render it probable that corrosive sublimate, before it can exert its remote action, must enter the blood; and the facts to be enumerated under the next head of the present section will render it probable that the milder compounds of mercury used in medicine also act in a similar manner. Physicians and chemists, therefore, long sought to discover this metal in the solids and fluids of the body while under its influence; and the failure of some attempts to detect it has naturally led to its presence throughout the system being called in question by many. This inquiry, besides its interest in a physiological point of view, is highly important in respect to medico-legal practice, since it forms a material branch of the general questions which at present occupy the attention of medical jurists,—whether poisons that act through the blood should be sought for by chemical analysis in other parts of the body besides the stomach, intestines, or other organ to which they have been directly applied—and in what particular quarters the search should be principally made.

In the case of mercury, the evidence of the absorption of the poison, and of its entering the tissues and secretions of the body, is now unimpeachable. This is chiefly derived from observations and experiments made on man and animals after the long-continued use of the milder preparations of mercury; it being imagined that if the poison enters the blood at all, the greatest quantity will be found under these circumstances. The facts may be arranged under three heads. Some relate to the discharge of metallic mercury from the living body during a mercurial course for medicinal purposes; others to the discovery of metallic mercury in the dead body after a mercurial course, and others to the detection of mercury by a careful chemical analysis in the fluids and solids during life or after death.

Many stories are related by the older authors of the discharge of running quicksilver from the living body during a mercurial course. Some of the most authentic of them have been collected by Zeller. In his list of cases it is stated that Schenkius met with an instance of the discharge of a spoonful of quicksilver by vomiting; that Rhodius twice remarked quicksilver pass with the urine; and that Hochstetter once saw it exhaled with the sweat.[861] Fallopius likewise states, that in people who had used mercurial inunction for three years, and who had the bones of the leg laid bare by suppurating nodes, he had seen quicksilver collected in globules on the tibia; and he speaks of its being the practice in his day to draw the mercury from the body, when overloaded with it, by successively amalgamating a bit of gold in the mouth and heating the amalgam to expel the mercury.[862] With regard to these statements of the older authors it may be observed that, although their singularity renders them questionable, they ought not to be rejected at once, as some have done, merely because corresponding facts have not been witnessed in modern times; for no one can now-a days have such opportunities for observation as were enjoyed by Fallopius and his contemporaries. The experiment of amalgamating gold in the mouth of a person under a course of mercury has always failed in modern times. But who can now have an opportunity of making the experiment during a mercurial course of three years? Besides, the statements quoted above are not all destitute of modern confirmation. Thus Fourcroy has noticed the case of a gilder attacked with an eruption of little boils, in each of which was contained a globule of quicksilver. Bruckmann mentions the case of a lady who subsequently to a course of mercury remarked after a dance many small black stains on her breast, and minute globules of quicksilver in the folds of her shift.[863] And Dr. Jourda has described in a late French periodical a case where fluid mercury was passed by the urine. The last fact appears satisfactory in all its circumstances. A patient had been taking corrosive sublimate for a month in the dose of a grain, besides using for the first sixteen days a gargle containing metallic mercury finely divided. Towards the close of the month he observed on the sill of the window, on which he used to turn up his chamber-pot after using it, many little globules of mercury, amounting in all to four grains. Dr. Jourda on learning this observation of his patient collected some of the urine with care, and after it had stood some time found in it a black, powdery sediment, which, when separated and dried, formed little globules of mercury.[864]

The next class of facts in favour of the entrance of mercury into the blood are derived from the discovery of the metal in the bodies of persons who had undergone a long mercurial course recently before death. In the German Ephemerides it is said that no less than a pound of it was found in the brain and two ounces in the skull-cap of one who had been long salivated.[865] This is certainly too marvellous a story. But analogous observations have been made lately. In Hufeland’s Journal it is mentioned that a skull found in a churchyard contained running quicksilver in the texture of its bones, and that there is preserved in the Lubben cabinet of midwifery a pelvis infiltered with mercury, and taken from a young woman who died of syphilis.[866] An unequivocal fact of the same nature has been related by Mr. Rigby Brodbelt. In a body of which he could not learn the history he found mercurial globules as big as a pin-head lying on the os hyoides, laryngeal cartilages, frontal bone, sternum, and tibia.[867] Another equally unquestionable fact of the kind has been supplied by Dr. Otto. On scraping the periosteum of several of the bones of a man who had laboured under syphilis, he remarked minute globules issuing from the osseous substance: in some places globules were deposited between the bone and periosteum, where the latter had been detached in the progress of putrefaction; and in other places, when the bones were struck, a shower of fine globules fell from them.[868] Wibmer observes that Fricke, surgeon to the Hamburg Infirmary, has obtained mercury by boiling the bones of persons who had been long under a course of mercurial inunction.[869]

The third and most satisfactory class of facts are the result of actual chemical analysis. These results were long variable. On the one hand, Mayer, Marabelli,[870] and Devergie,[871] failed to detect mercury in the fluids of people under a mercurial course; and I myself,[872] as well as Dr. Samuel Wright,[873] had no better success in some experiments on animals. On the other hand, Zeller detected it after death in the blood and bile, Cantu procured it from the urine, Buchner found it in the blood, saliva, and urine, and Schubarth extracted it from the blood. The first experimentalist found that in the blood and bile of animals killed by mercurial inunction, mercury could be detected by destructive distillation, but not by any fluid tests.[874] Cantu, by operating on sixty pounds of urine, taken from persons under the action of mercury, procured no less than twenty grains of the metal from the sediment.[875] The experiments of Buchner are very satisfactory. By destructive distillation of the crassamentum of seven ounces of blood taken from a patient who was salivated by mercury, he obtained rather more than a quarter of a grain of globules; two pounds of saliva yielded in the same way a 200th of a grain; and the urine contained so much that it became brownish-black with sulphuretted-hydrogen.[876] Buchner likewise adds, that Professor Pickel of Würzburg procured mercury by destructive distillation from the brain of a venereal patient who had long taken corrosive sublimate.[877] Not less satisfactory are the experiments of Dr. Schubarth. A horse after being rubbed for twenty-nine days with mercurial ointment to the total amount of eighty ounces, died of fever, emaciation, diarrhœa, and ptyalism. On the sixteenth day, when ptyalism had set in, a quart of blood was drawn from the jugular vein, and after death another quart was collected from the heart, great vessels and lungs,—extreme care being taken to collect it perfectly pure. In each specimen there was procured by destructive distillation a liquor, in which minute metallic globules were visible. A copper coin agitated in the liquor was whitened; and when the oily matter was separated by filtration and boiling in alcohol, the residue gave with nitric acid a solution, which produced an orange precipitate with hydriodate of potass.

These researches were considered adequate to prove the strong probability of the absorption of mercurial preparations when introduced into the animal. But the frequency with which negative results were obtained by competent inquirers, and in circumstances apparently favourable, threw an air of doubt over the positive facts, however clear they seem to be in themselves,—till at length Professor Orfila proved by a series of careful experiments that the cause of failure must generally have been the want of a process sufficiently delicate: for in all ordinary circumstances, by using his process described above, he succeeded in obtaining mercury in the urine and liver of animals poisoned with corrosive sublimate, as well as in the urine of patients who were taking that salt in medicinal doses. He could not detect it, however, in the blood.[878] Since these investigations, Professor Landerer of Athens detected mercury in the brain, liver, lungs and spinal cord of a man who poisoned himself with two ounces and a half of corrosive sublimate;[879] and M. Audouard has twice found it in the urine and once in the saliva of persons salivated with mercury, by simply transmitting chlorine, exposing the liquid to the air for a day, evaporating it nearly to dryness, dissolving the residue in water slightly acidulated with hydrochloric acid, immersing copper-leaf for twenty-four hours, and heating the stained portions in a tube.[880]

The cases of poisoning with the preparations of mercury, which have been observed in the human subject, may be conveniently arranged under three varieties. In one variety the sole or leading symptoms are those of violent irritation of the alimentary canal. In another the symptoms are at first the same as in the former, but subsequently become united with salivation and inflammation of the mouth, or some of the other disorders incident to mercurial erethysm, as it is called. In a third variety the preliminary stage of irritation in the alimentary canal is wanting, and the symptoms are from beginning to end those of mercurial erethysm in one or another of its multifarious forms.

The first variety of poisoning with mercury is remarked only in those who have taken considerable doses of its soluble salts, particularly corrosive sublimate. The second is produced by the same preparations. The third may be caused by any mercurial compound.

1. The symptoms in the first variety are very like what occur in the ordinary cases of poisoning with arsenic,—namely, vomiting, especially when any thing is swallowed, violent pain in the pit of the stomach, as well as over the whole belly, and profuse diarrhœa. But there exist between the effects of the two poisons some shades of difference which it is necessary to attend to.

In the first place,—taking corrosive sublimate as the best example of the preparations which cause this variety of poisoning with mercury,—the symptoms generally begin much sooner than those caused by arsenic. The symptoms of irritation in the throat may begin immediately, nay, even during the very act of swallowing;[881] and those in the stomach may appear either immediately,[882] or within five minutes.[883]

Secondly, the taste is much more unequivocal and strong. Even a small quantity of corrosive sublimate, either in the solid or fluid state, and considerably diluted, has so strong and so horrible a taste, that no one could swallow it in a form capable of causing much irritation in the stomach, without being at once made sensible by the taste that he had taken something unusual and injurious. Occasionally, indeed, persons thus warned of their danger while in the act of swallowing the poison, have stopped in time to escape fatal consequences.[884]

Thirdly, the sense of acridity which it excites in the gullet during the act of deglutition, and throughout the whole course of the subsequent inflammation of the alimentary canal, is usually much stronger. If the dose be not small, or largely diluted, or in the solid form, the sense of tightness, acridity, or burning in the throat and gullet during deglutition is often far greater than ever occurs at any stage in the instance of arsenic; and sometimes it is very severe even when corrosive sublimate is taken in the solid form.[885] The tightness and burning in the throat often continue throughout the whole duration of the poisoning; and may be so excessive as to cause complete inability to swallow,[886] or even to speak.[887] Occasionally the affection of the throat is the only material injury inflicted by the poison, as in a case related by Dr. J. Johnstone of a young woman, who tried to swallow two drachms of corrosive sublimate in the solid state, but was unable to force it down on account of the constriction it caused in the gullet. She died in six days of mortification of the throat.[888] The greater violence of the action of corrosive sublimate on the throat, compared with that of arsenic, is evidently owing to its greater solubility and powerful chemical operation on the animal textures.

Fourthly, instead of the contracted ghastly countenance observed in cases of poisoning with arsenic (but which, it will be remembered, is not invariable in that kind of poisoning), those who are suffering under the primary effects of corrosive sublimate have frequently the countenance much flushed, and even swelled.[889]

Corrosive sublimate seems to occasion more frequently than arsenic the discharge of blood by vomiting and purging,—obviously because it is a more powerful local irritant.

It likewise gives rise more frequently to irritation of the urinary passages. This irritation generally consists in frequent, painful micturition; but the secretion of urine is often suppressed altogether. Instances of this kind have been related by Mr. Valentine,[890] by my colleague, Professor Syme,[891] by an anonymous writer in the Medical and Physical Journal,[892] by Dr. Venables,[893] by Mr. Blacklock,[894] and by M. Ollivier, in whose case, however, the poison was the bicyanide of mercury.[895] In the last three cases the suppression was total, and continued till death; which did not ensue, in one till eight, in the next till five, and in the last till nine days after the poison was taken. Sometimes, as in Ollivier’s case, the urinary irritation is attended with symptoms of excitement of the external parts, such as swelling and blackness of the scrotum and erection of the penis.

Another distinction seems to be that corrosive sublimate is more apt than arsenic to cause nervous affections during the first inflammatory stage. The tendency to doze, which sometimes interrupts the inflammatory symptoms caused by arsenic, has been more frequently observed in cases of poisoning with corrosive sublimate.[896] The same may be said of tremors and twitches of the extremities. Sometimes the stupor approaches even to absolute coma;[897] and the twitches occasionally amount to distinct, nay violent convulsions.[898] In other instances paraplegia has been witnessed.[899]

Another difference is, that the effects of mercurial irritants are fully more curable than those of arsenic. Recovery has taken place even after half an ounce was swallowed, with the effect of inducing both bloody vomiting and purging.[900] This may depend in part on the greater solubility of mercurial preparations, so that they are more easily discharged than arsenic, which often remains in the stomach after days of continual vomiting,—and in part on corrosive sublimate and other soluble salts of mercury being converted, in no long time and much more easily, into comparatively innocuous compounds, either by antidotes intentionally given for the purpose, or by animal principles in the secretions and accidental contents of the alimentary canal.

Lastly, deviations from the ordinary course and combination of the symptoms appear to be more rare in the instance of corrosive sublimate than in that of arsenic.

To these general statements, it may be right to add the heads of one or two actual cases, lest an exaggerated idea be conveyed of the combination of the symptoms as they usually occur. For this purpose it will be sufficient to refer to a fatal case related by M. Devergie, to an instance of recovery, without salivation having supervened, which is contained in Orfila’s Toxicology, and to another by Dr. Vautier, presenting the mildest possible symptoms of this variety. In Devergie’s case, the patient, a female, swallowed three drachms of corrosive sublimate in solution, and was soon after seized with vomiting, purging, and pain in the belly. In five hours, when she was first seen by Devergie, the skin was cold and damp, the limbs relaxed, the face pale, the eyes dull, and the expression that of horror and anxiety. The lips and tongue were white and shrivelled; and she had dreadful fits of pain and spasm in the throat whenever she attempted to swallow liquids, also burning and pricking along the course of the gullet, and increase of pain in these parts on pressure. There was likewise frequent vomiting of mucous and bilious matter, with burning pain in the stomach and tenderness of the epigastrium on the slightest pressure. She had farther profuse diarrhœa, with pricking pain and tenesmus. The pulsation of the heart was deep and slow, the pulse at the wrist almost imperceptible, and the breathing much retarded. In eighteen hours these symptoms continued without any material change; but the limbs were also then insensible. In twenty-three hours she died in a fit of fainting, the mind having been entire to the last.[901]—Orfila’s case was that of a gentleman who drank by mistake an alcoholic solution of corrosive sublimate, but fortunately was so much alarmed by its taste while drinking it, that he did not finish the poisonous draught. Nevertheless, he was instantly attacked with a sense of tightness in the throat and burning in the stomach, and then with vomiting and purging. Two hours after the accident Orfila found him with the face very full and red, the eyes sparkling and restless, the pupils contracted, and the lips dry and cracked. There was also acute pain along the whole course of the alimentary canal, particularly in the throat. The belly was swelled, and so tender that he could not bear the weight of fomentation-cloths. The pulse was 112, small and sharp; the skin intensely hot and pungent; micturition scanty, frequent, and difficult; the breathing very much oppressed; the purging bilious. The patient had likewise a tendency to doze, and was affected with occasional convulsive twitches of the face and extremities, and with constant cramps in the limbs. Next morning all the symptoms were sensibly mitigated; and they went on decreasing till convalescence was established in eight days. In the course of a few weeks he recovered his usual health, without suffering salivation.[902]—In Vautier’s case, where sixteen grains had been swallowed, the patient was immediately attacked with pain in the throat and stomach, cold extremities, trembling of the arms and legs, vomiting, paleness of the features, and great feebleness of the pulse. Vomiting being promoted by frequent draughts of warm water, and white of egg given subsequently, no further symptoms ensued, those first excited slowly subsided, and in a few days recovery took place, without any salivation. Yet it was upwards of half an hour before any measures could be taken for his relief.[903]

The only material and common symptom which was wanting in the case now related was blood in the stools and in the matter vomited. In other respects they are good examples of the ordinary train of symptoms in cases of the present variety. For other examples of the same nature the reader may refer particularly to the paper of Mr. Valentine, who has described five cases that happened at one time in the same family, the mother having attempted to poison herself and four children.[904]

It may sometimes be necessary to know the usual duration of this variety of mercurial poisoning, and also the extremes of its duration. On these points I have not hitherto had opportunities of consulting a sufficient number of cases to be able to lay down the general rule with precision. But, so far as my inquiries go, the ordinary duration in fatal cases is from twenty-four to thirty-six hours. It is probable that a few may last three days,[905] but only one instance has come under my notice where the duration was greater; and in that instance, which is described by Dr. Venables, life was prolonged under great agony from pain of the belly, bloody vomiting, diarrhœa and suppression of urine, but without salivation, for no less than eight days.[906] In cases of recovery the symptoms of irritation may continue very long, and nevertheless not pass into the second variety of this kind of poisoning,—a transition, however, which on the whole is uncommon. In the case of which an analysis has been given from Orfila’s narrative, and likewise in one of Mr. Valentine’s patients who recovered, the symptoms all along were those of irritation in the alimentary canal; there was not any ptyalism, or other symptom of proper mercurial erethysm.—The shortest duration yet recorded is two hours and a half. This was in a case related by Dr. Bigsby of Newark-on-Trent, where a tea-spoonful of a concentrated solution of nitrate of mercury was swallowed by a lad sixteen years old, and where the chief symptoms were burning pain from the mouth to the stomach, tenderness of the whole belly, mucous vomiting, and feculent purging.[907] In a case which occurred in London, and which has been published succinctly by Mr. Illingworth, death must have occurred either as soon, or very shortly afterwards. The dose of corrosive sublimate, though not positively ascertained, was large.[908] Next to this the shortest case recorded proved fatal in eleven hours.[909]

2. The second variety of poisoning with mercury comprehends the cases, which begin, like the former, with irritation in the alimentary canal, but in which the symptoms of what is called mercurial erethysm gradually supervene. In fatal cases of this description death sometimes arises from the primary action of the poison, exactly as in the previous variety; but in other instances it is owing to general disturbance of the constitution, or the local devastation, brought on by the secondary effects.

It is unnecessary to describe here the several forms of mercurial erethysm which may thus be developed, because they will immediately be considered under the third variety of mercurial poisoning. It is sufficient to state in passing that the leading affection is inflammation of the organs in and adjoining the mouth, and more particularly of the salivary glands.

But it may be right to endeavour in the present place to fix the period of the poisoning at which these secondary affections may and usually do commence. This cannot be done so satisfactorily as might be wished, because the cases already published which I have been able to examine do not form a large enough induction. Among the recorded cases I have hitherto seen, salivation has never been retarded beyond the third day;[910] but in an instance of suicide by corrosive sublimate which happened in the Castle of Edinburgh in 1826, and which was communicated to me by the late Dr. Shortt, the salivation did not begin till the fourth. Salivation seldom comes on sooner than the beginning of the second;[911] and the most usual date of its commencement is towards the close of the second day. There is little doubt that it may be retarded till a period considerably later than I have yet found recorded. It is doubtful whether true mercurial salivation ever begins much sooner than after the first twenty-four hours. Occasionally, however, corrosive sublimate produces salivation of a different kind, which has been mistaken for the specific variety caused by mercury. Thus in a paper on the cure of gonorrhœa by corrosive sublimate in single large doses, communicated by Mr. Addington of West Bromwich to Dr. Beddoes, it is stated that a grain and a half, taken at once in half an ounce of rectified spirit, causes immediately “a great burning in the throat and stomach, and quickly afterwards a copious salivation, lasting between an hour and a half and two hours, and amounting frequently to more than a quart.”[912] These facts have been appealed to by authors in medical jurisprudence as proving the rapid production of mercurial salivation. But the effect produced is not the specific ptyalism of mercury; for its brief duration is scarcely consistent with this supposition. And farther, the author goes on to observe, that, if the dose be taken on going to bed, the latter part of the night is passed quietly, and no inconvenience is felt afterwards, even when the dose is taken five or six times at intervals of three or four days. The effects here observed is a sympathetic phenomenon depending on the topical action of the poison. And such, I have no doubt, has been the nature of the salivation in several cases of poisoning with corrosive sublimate, which have been supposed to be at variance with the general rule, that this affection does not begin till about twenty-four hours have elapsed. Such seems to have been the nature of the salivation in a case published by Dr. Perry,[913] that of a girl who was attacked with swelling of the cheeks and lower lip, burning in the throat, flushed face, feeble pulse, and cold, clammy extremities after swallowing corrosive sublimate, and who had a copious flow of saliva in an hour and a half; for there is no mention made of fetor, and the girl was well enough to leave the hospital in a few days,—which could scarcely happen if she had been affected with ptyalism from the constitutional action of mercury.—In like manner Dr. Alexander Wood has related a case, fatal in fourteen days, in which the patient said salivation came on in seven hours.[914] But, notwithstanding Dr. Wood’s argument in support of the patient’s statement,—for he did not see him till nine days after the poison was taken,—there is no satisfactory evidence that the salivation was the true constitutional salivation of mercury, and not simply the result of its topical action, which seems to have been very severe.—Farther, in an instance related by Dr. H. Anderson of Belfast, where salivation appeared to him to begin in nineteen hours, it seems not improbable that he mistook for mercurial ptyalism the common salivation arising from inability to swallow on account of sore throat; for this patient too was quite convalescent in three days.[915]—Mr. Alfred Taylor alludes to a case in Guy’s Hospital of salivation occurring in four hours; but so briefly, that its true influence on the present question cannot be judged of.[916]—On the whole, then, although it is clear that ptyalism of one kind or another may occur very soon after corrosive sublimate is swallowed, it remains a matter of doubt, whether the true, specific ptyalism, depending on the constitutional action of the poison begins sooner than after an interval of above twenty-four hours.

As to the total duration of this variety in fatal cases, I have found an instance fatal on the fourth day, salivation having begun on the second;[917] and Orfila quotes a case from Degner, in which the gastro-enteritic symptoms were succeeded by ptyalism about the same period, and which proved fatal in fifteen days.[918] These periods, however, probably do not form the extremes; for in such cases as the former death is the consequence of the primary affection, and may therefore ensue immediately after the secondary stage has begun to develope itself; and when death arises from profuse salivation, as in Degner’s patient, or from the ravages committed by ulceration and gangrene, it may be delayed almost as long as in cases of the third variety of mercurial poisoning, in which there is no precursory stage of inflammation in the alimentary canal.

Death may arise, not only from the primary action of the poison, or from the exhaustion caused by mercurial erethysm, but likewise from incidental occurrences. Thus, in Dr. Alexander Wood’s case, referred to above, death arose directly from sudden profuse hemorrhage from the bowels, to the amount of six pounds.

The present variety of poisoning with corrosive sublimate may be concluded with the heads of an excellent example related in the Medical and Physical Journal. The patient, a stout young girl, swallowed soon after supper a drachm of corrosive sublimate dissolved in beer, and in a few minutes she was found on her knees in great torture. All the primary symptoms of this kind of poisoning were present in their most violent form,—burning in the stomach, extending towards the throat and mouth, followed in no long time by violent vomiting of a matter at first mucous, afterwards bilious and bloody; by purging of a brownish, fetid fluid; suppression of urine and much tenderness of the urethra and bladder; small, contracted, frequent pulse, anxious countenance, and considerable stupor, interrupted frequently by fits of increased pain. All these symptoms were developed in four hours. Subsequently the pain in the stomach became much easier, but that in the throat much worse. At length in the course of the second day, the teeth became loose, the gums tender, the saliva more abundant than natural; profuse ptyalism and great fetor of the breath ensued, and the patient expired towards the close of the fourth day.[919]

3. The third variety of poisoning with mercury comprehends all the forms of what is called mercurial erethysm. Without endeavouring to settle the precise meaning of this term, which is now used in rather a vague sense, I shall consider under the present head all the secondary and chronic effects of mercury. These may be caused by any of its preparations, but are most frequently seen as the consequence of its milder compounds, either given medicinally in frequent small doses, or applied continuously to the bodies of workmen who are exposed by their trade to its fumes.

The secondary and chronic effects of mercury are multifarious enough in reality; but if credit were given to all that has been written, and is still sometimes maintained on this subject, almost every disease in the nosology might be enumerated under the present head; for there is scarcely a disease of common occurrence, which has not been imputed by one author or another to the direct or indirect operation of mercury. The present remarks, however, will be confined as much as possible to what is well ascertained, and bears on the medical evidence of poisoning with mercury, or is important in regard to medical police. With this view, salivation and its concomitants, the most usual of the secondary effects of mercury, will first be treated of. Some observations will then be made on the shaking palsy, or mercurial tremor, which is caused in those who work with mercury. And in conclusion, a short view will be taken of the other diseases which are more indirectly induced by this poison, as well as some which have been ascribed to it on insufficient grounds. This being done, the mode of action of mercurial poisons will be resumed, and a description given of their relative effects when introduced by different channels and in different chemical forms.

_Of Mercurial Salivation._—Mercurial salivation may be caused by any of the preparations of mercury, and either by a single dose or by frequently repeated small doses. It may be caused by corrosive sublimate as the secondary stage of a case which commenced with inflammation in the alimentary canal; or it may be the first sign of mercurial action, as in the medicinal mode of administering calomel and blue pill. Even in the latter case a single dose, and that not large, may be sufficient to induce ptyalism of the most violent kind. When induced by a single dose it usually commences between the beginning of the second and end of the third day, rarely within twenty-four hours. But an extraordinary case is mentioned by Dr. Bright, where five grains, put on the tongue in apoplexy and not washed over, excited in three hours most violent salivation, with such swelling of the tongue that scarifications became necessary.[920] It commences with a brassy taste and tenderness of the mouth, swelling, redness, and subsequently ulceration of the gums; peculiar fetor of the breath; and at last an augmentation is observed in the flow of the saliva, commonly accompanied with fulness around the lower jaw. These symptoms increase more or less rapidly. Sometimes they are very mild; nay, this form of the secondary effects of mercury may consist in nothing else than brassy taste, tenderness of the mouth, redness of the gums, and fetor. On the other hand, the symptoms are often very violent, the salivation being profuse, the face swelled so as to close the eyes, and almost fill up the space between the jaw and clavicles, the tongue swollen so as to threaten suffocation, the inside of the mouth ulcerated, nay gangrenous, and at times the gangrene extends over the face. It is not uncommon to observe severe and extensive ulceration without particular increase of the saliva.

These local affections are almost always accompanied with more or less constitutional disorder. If severe, they are attended with the symptomatic fever proper to inflammation and gangrene, from whatever cause they spring. But independently of that, mercurial salivation is accompanied, and indeed commonly preceded, by a constitutional disorder or symptomatic fever of its own, which occasionally exhibits some peculiarities. The mildest affection of the mouth and salivary glands is very generally preceded by some exaltation of the pulse and temperature, and other symptoms of fever. But when the local disorder begins violently, and above all when this takes place by idiosyncrasy from small doses of mild preparations, there is often great rapidity of the pulse, irregular action of the heart, and various nervous disorders possessing the hysteric character,—all of which, except the quick pulse, will sometimes gradually abate or even disappear, when the salivation is fairly established.

The phenomena of ordinary mercurial salivation being familiar to every practitioner, it is unnecessary to quote here any illustrative example; but the following instance may be given to exemplify its most malignant forms. A patient of Mr. Potter of Chipping-Ongar, in Essex, after taking eighteen grains of blue pill in divided doses during three days, was seized with excessive salivation and great constitutional disturbance, indicated by offensive evacuations, copious sweating, bleeding from the nose, purple spots on the skin, dilated pupils, and such severe local disease that the teeth dropped out, and he expired six days after mercurial action set in.[921]

As the phenomena of mercurial salivation have been often known to lead to important evidence and much contrariety of opinion upon trials, it will be necessary to dwell at some length on some parts of the subject.

In the first instance, then, the dose which is required to bring on salivation may be noticed. It is needless to mention the ordinary quantity required in mercurial courses. A more useful object of consideration is the departure from the ordinary rule. One of the most common and important of these deviations is excessive sensibility to the action of mercury, in consequence of which the individuals who have this idiosyncrasy may be profusely salivated by one or two small doses even of the mildest preparations. Three grains of corrosive sublimate divided into three doses have caused violent ptyalism.[922] Fifteen grains of blue pill, taken in three doses, one every night, have excited fatal salivation.[923] Nay, two grains of calomel have caused ptyalism, extensive ulceration of the throat, exfoliation of the lower jaw, and death.[924] Three drachms of mercurial ointment applied externally have caused violent ptyalism and death in eight days. On the other hand, it is well known that some constitutions resist the action of mercurials very obstinately, so as even sometimes to appear incapable of being salivated at all. I have more than once met with cases of the last description, where mercurial courses had been continued for three months and upwards without avail. It may be added, that, except in constitutions naturally predisposed to suffer from a few small doses, a few large doses do not appear apt to excite severe salivation, or even to cause any at all. This has been clearly shown in the course of the practice lately introduced of administering calomel in doses of a scruple. On that subject more will be said by and by. At present I may mention, that, in conformity with the practice alluded to, I have several times, in various diseases, given eight or ten grains of calomel five or six times a day for two or three days together, without observing that ptyalism was apt to ensue.

The next point to be considered is, whether mercurial salivation can be confounded with any other affection. In a very difficult case of poisoning which was tried here in 1817, that of William Patterson for murdering his wife,[925] it appeared probable that he had given her repeatedly large doses of calomel. But the proof of this was circumstantial only, and an important circumstance in the chain of evidence was a deposition to the occurrence of salivation during the woman’s illness. This fact, however, rested on the skill and testimony of a quack doctor only; and the admissibility of such a person to decide on a point of this nature, will depend on the facility with which the true mercurial form of salivation can be recognised. This statement will show the practical object of what is to follow.

Many other causes may excite a preternatural flow of saliva. Several other poisons may have that effect, for example, preparations of gold, preparations of copper, antimony, croton-oil, and foxglove: foxglove has been known to cause violent salivation for three weeks.[926] Opium too has occasionally excited salivation,[927] and also hydrocyanic acid and iodide of potassium.

Even a common sore throat, if the swelling and pain are so great as to render swallowing very difficult and distressing, may be accompanied, as every physician must have remarked, with a profuse flow of saliva; and in the ulcerative stage there is also often a fetor that is hardly distinguishable from the mercurial kind. In the ulceration of the mouth called _cancrum oris_ there is some salivation with great fetor of the breath.

Salivation likewise forms an idiopathic disease, and may then be both profuse and obstinate. Mr. Davies has described a case of spontaneous ptyalism which had lasted for a fortnight before he was called to see the patient; and during all that time the quantity of saliva discharged was two or three pints daily. How long it endured afterwards he does not mention; but it must have continued for some time, because during his attendance first one physician and then another were called into consultation with him. Laxatives slowly removed it. Mr. Davies has not described the state of the mouth; but the first physician mistook the salivation for a mercurial one.[928] In the same journal which contains this case another has been related which lasted four months.[929] Another very remarkable case has been recorded by Mr. Power. The patient, a young lady, discharged for more than two years from sixteen to forty ounces of saliva daily. In the last two cases the mouth was not affected.[930] Two other instances have been related by M. Bayle, in one of which the patient was cured after spitting five pounds daily for nine years and a half; while the other continued to be affected after spitting profusely for three years. In neither was there any ulceration of the mouth.[931] An instance has been related by an Italian physician, Dr. Petrunti, where, in the course of various nervous affections of the hysteric character, the patient became affected with heat and tightness in the throat, and so profuse a salivation for two months, that between three and four pounds were discharged daily.[932] A case somewhat similar is related in Rust’s Magazin of a man who suffered upwards of two years from a daily salivation alternating occasionally with a mucous discharge from the bowels or lungs.[933] M. Guibourt describes the case of a lady who had an attack of profuse salivation every thirty, forty, or fifty days, lasting between twenty-four and forty-eight hours, and unaccompanied with any other affection of the mouth or adjoining parts except a sense of tightness in the throat.[934] M. Gorham relates an interesting case of a lady who in three successive pregnancies was attacked soon after impregnation with excessive ptyalism, which continued to the extent of between two and four quarts daily until the period of quickening on two occasions, and on the third till her delivery; but there was never any fetor or any affection of the gums.[935] I have likewise met with a singular case where spontaneous ptyalism accompanied an ulcerated sore throat of the mercurio-syphilitic kind. The patient had taken mercury to salivation about six months before coming under my care, and got completely rid of both the sore throat and salivation. But the sore throat returned, together with the salivation, two months before I saw him, and the salivation continued for two months longer to the extent of twenty or even thirty ounces daily,—the ulcer of the throat during that interval being sometimes healed up, and again returning as severely as ever. In three weeks more the discharge rapidly diminished, and ceased. During all the time he was under my care there was no fetor of the breath, and no redness, ulceration, or sponginess of the gums. A singular account of an epidemic salivation which occurred in connection with a continued tertian fever, has been given in an inaugural dissertation contained in one of Haller’s Collections. The author, Quelmalz, says that the ptyalism sometimes continued for three weeks, that it was in one instance as great in extent as the most violent mercurial salivation, and that it was accompanied by fetor, superficial ulceration of the mouth, pustules on the tongue, relaxation of the gums, and looseness of the teeth.[936]

Salivation may likewise be produced by the influence of the imagination. I have seen a singular example of this. A woman who had a great aversion to calomel was taking it with digitalis for a dropsical complaint. Some one having told her what she was using, she immediately began to complain of soreness of the mouth, salivated profusely, and even put on the expression of countenance of a salivating person, although she had taken only two grains. On being persuaded, however, that she had been misinformed, the discharge ceased gradually in the course of one night. Two days afterwards she was again told on good authority that calomel was contained in her medicines, upon which the salivation began again and was profuse. It did not last above twenty-four hours; but the symptoms during that period resembled a commencing mercurial salivation in every thing but the want of fetor and redness of the gums.

In general, mercurial salivation may be easily distinguished from all the preceding varieties by an experienced practitioner. If its progress has been traced from the first appearance of brassy taste and fetor to the formation of ulcers and supervention of ptyalism, no attentive person can run any risk of mistaking it. Its characters are also quite distinct at the time salivation just begins. The fetor of the breath and sponginess and ulceration of the gums at this stage distinguish it from every other affection. But if the state of the mouth is not examined till the ulcers have existed several days, the characters of the mercurial disorder are much more equivocal. They cannot be distinguished, for example, from some forms of idiopathic ulceration of the mouth connected with unsoundness of the constitution, and characterized by extensive sloughing, ptyalism, and gangrenous fetor.[937] In particular they cannot be distinguished from the effects of the disease called _cancrum oris_. A few years ago indeed a London physician was charged, in consequence of this resemblance, with having killed, by mercurial salivation, a patient to whom it was proved that he had not given a particle of mercury, and who clearly died of the disease in question;[938] and a similar case, where fatal mercurial salivation was suspected, but which was clearly proved on a Coroner’s Inquest to have been also a case of cancrum oris, has been more lately published by Mr. Dunn.[939]

For distinguishing these and such other affections from mercurial salivation Dr. Davidson of Glasgow has lately proposed a character, the exact scope of which cannot yet be appreciated,—namely, that in true mercurial salivation there is never any sulpho-cyanic acid in the saliva; so that sesquichloride of iron does not render it red. The presence of sulpho-cyanic acid may possibly prove that salivation is not mercurial; but the converse does not hold good, because other causes tend to deprive human saliva of its sulpho-cyanic acid.[940]

The next point to be noticed regarding mercurial salivation is, that a long interval may elapse after the administration of the mercury has been abandoned, before the effect on the salivary glands and mouth begins,—mercury in small doses being what is called a cumulative poison, or a poison whose influence accumulates silently for some time in the body before its symptoms break forth. Swédiaur has met with instances where the interval was several months,[941] Cullerier with a case in which it was three months.[942] It will at once be seen how strongly such facts may bear on the evidence in a criminal case, where the administration of mercury in medicinal doses, which have been long abandoned, is brought forward to account for salivation, appearing weeks or months after, and giving rise, in conjunction with other circumstances, to a suspicion of mercurial poisoning of more recent date.

Another question which has been made the subject of discussion is the duration of mercurial ptyalism. The medical witness may be required to give his opinion how long this affection may last after the administration of mercury has been abandoned. The present question may be cut short by stating, that there appears to be hardly any limit to its possible duration. Linnæus met with an instance of its continuing inveterately for a whole year;[943] Swédiaur says he has known persons languish for months and years from its effects;[944] and M. Colson knew an individual who had been salivated for six years.[945] These, however, are very rare incidents. After an ordinary mercurial course the mouth and salivary glands generally return to the healthy state in the course of a fortnight or three weeks.

A fifth question, whether the ptyalism, or, speaking in general terms, the erethysm of mercury, is susceptible of a complete intermission, formed a material subject of inquiry, and the cause of much contradictory statement on a noted criminal trial, that of Miss Butterfield in 1775 for the murder of her master, Mr. Scawen. She was accused of administering corrosive sublimate; and it was alleged in her defence, that the salivation and consequent sloughing of which he died might have arisen, without the fresh administration of mercury, from the renewal of a previous ptyalism, which had been brought on by a common mercurial course, and had ceased two months before the second salivation began. It appeared that Mr. Scawen was salivated with a quack medicine from the beginning till the middle of April; and that about the middle of June he was again seized with violent salivation, of which he died. It was rendered very improbable, that during the interval between the two salivations any more mercury had been taken medicinally. The question then was, whether the original ptyalism could have reappeared after so long an interval, without the fresh administration of mercury? The witnesses for the prosecution, gentlemen in extensive practice, said it could not. But one of the prisoner’s witnesses, Mr. Bloomfield of the London Lock Hospital, said he had repeatedly known salivation reappear after a long intermission; that it was quite common for hospital patients to have a second salivation, when thought well enough to go out the next dismissal day;[946] that in one case the interval was three months; and that one of his patients was attacked periodically with salivation at intervals of six weeks or a month for a whole year. Mr. Howard, another surgeon of the Lock Hospital, deposed to the same effect; and the prisoner was acquitted, apparently upon their evidence.[947]

Notwithstanding what was said by these gentlemen, I believe the recurrence of mercurial salivation after so long an interval, without the repetition of mercury, is exceedingly rare. Dr. Gordon Smith, in alluding to the trial of Miss Butterfield, has mentioned a case which occurred to the late Dr. Hamilton of this University, and used to be related by him in his lectures. The interval was so great as four months.[948] Mr. Green of Bristol has lately described another unequivocal case, where the interval was six weeks.[949] Dr. Mead says he met with an instance where the interval was six months;[950] and Dr. Male mentions another where mercury brought on moderate salivation in March, and after a long interval excited a fresh salivation in October, of which his patient died in a few weeks.[951] M. Louyer-Villermé met with a case, where, in consequence of exposure to cold, a sudden attack of salivation was caused a twelvemonth after the removal of syphilis by mercury.[952] Some other cases not less wonderful have been recorded by M. Colson in his paper on the effects of mercury. He quotes Dr. Fordyce for the case of a man who had repeated attacks of salivation, with metallic taste, which lasted for three weeks, although mercury had not been taken for twelve years; and Colson himself knew a surgeon who had a regular and violent attack of all the symptoms of mercurialism eight years after he had ceased to take mercury.[953] It is impossible to attach credit to such marvellous stories as the last two. Granting the ptyalism to be really mercurial, it would require much better evidence than any practitioner could procure, to determine the fact that mercury had not been given again during the supposed interval. This objection indeed will apply more or less even to the instances where the alleged interval did not exceed a few months.

The last point to be noticed regarding mercurial salivation is the manner in which it proves fatal. Death may ensue from the mildest preparations, and from the smallest doses, in consequence of severe salivation being produced by them in peculiar habits. Two instances have been already mentioned which illustrate both of these statements, and others might easily be referred to were the fact not familiar.

Death may be owing to a variety of causes. Some of those which have been assigned are direct and unquestionable in their operation; others indirect and more doubtful.

The most direct and obvious manner is by extensive spreading gangrene of the throat, mouth, face, and neck. The late happy changes, introduced into the treatment of syphilis and other diseases which are benefited by mercury, render this mode of death rare in the present day. Yet I may mention that I have seen an example of it in a woman who was salivated to death, because her medical attendant, a firm believer in the powers of mercury as an antidote, forgot that the antidote is itself a poison, if not given in moderation. In general, when gangrene is the cause of death, it begins within the mouth or in the throat, and spreads from that till it even reaches the face. But sometimes it begins at once on the external surface, at a distance from the primary ulcers. An example of such a progress of the symptoms has been related by Dr. Grattan. A child ten years old was violently salivated by twenty grains of calomel given in six days. On the fifth day of the salivation, a little vesicle appeared on the skin near the mouth on each side, and was the commencement of a gangrenous ulcer, which spread over the whole cheek, and proved fatal eight days after its appearance.[954]

Another cause of death appears to be exhaustion from profuse and protracted discharge of saliva, without material injury of the mouth or adjoining organs.

A third manner of death which I have witnessed is exhaustion from laryngeal phthisis; and from the circumstances of the case, I have little doubt but, in the state to which patients are then sometimes reduced, death may also take place suddenly from suffocation. My patient had undergone before I saw him five long salivations for a venereal complaint, and had latterly been attacked with symptoms of ulceration of the glottis. This affection went on slowly increasing, and he died of exhaustion after many weeks of suffering. During this period he was repeatedly attacked with alarming fits of suffocation, which were relieved by the hawking of mucous flakes. The symptoms were explained on dissection by the appearance of extensive ulceration and thickening of the glottis, and almost total destruction of the epiglottis.

The other causes of death are more indirect, and will be mentioned presently. They depend on the pre-existence of other diseases, on which mercury acts deleteriously during the state of erethysm excited by it in the constitution.

_Of Mercurial Tremor._—The second division of the secondary effects of mercury comprehends the palsy or tremor, with the collateral disorders induced in miners, gilders, and other workmen, whose trade exposes them to the operation of this poison. Under the present head, which might be treated at considerable length as an important branch of medical police, I shall confine myself chiefly to an analysis of an interesting essay by Mérat on the _Tremblement Metallique_, and to some remarks by Jussieu on the health of the quicksilver miners of Almaden in Spain.

Mérat’s account of the shaking palsy induced by mercury is very interesting.[955] The disease, he states, may sometimes begin suddenly; but in general it makes its approaches by slow steps. The first symptom is unsteadiness of the arms, then quivering, finally tremors, the several movements of which become more and more extensive till they resemble convulsions, and render it difficult or impossible for the patient to walk, to speak, or even to chew. All voluntary motions, such as carrying a morsel to the mouth, are effected by several violent starts. The arms are generally attacked first and also most severely. If the man does not now quit work, loss of memory, sleeplessness, delirium, and death ensue. But as the nature of the disease soon renders working almost impossible, he cannot well continue; and in that case death is rare. The concomitant symptoms of the trembling are a peculiar brown tint of the whole body, dry skin, flatus, but no colic, no disorder of respiration, and, except in very old cases, no wasting or impaired digestion. The pulse is almost always slow.—This description agrees with a somewhat later account of the disease by Dr. Bateman, as he observed it in mirror-silverers;[956] and also with some interesting cases recently published by Dr. Bright.[957]

In general the tremors are cured easily, though slowly, several months being commonly required. One of Dr. Bright’s patients got almost well in little more than a fortnight under the use of sulphate of zinc. Sometimes, however, the trembling is incurable.[958] I have said the disease is rarely fatal. Mérat quotes three cases only, in one of which death was owing to profuse salivation and gangrene, in the others to marasmus. On the whole, those who are liable to the shaking palsy do not appear liable to salivation. Yet the two affections are sometimes conjoined, as in three of the cases described by Dr. Bright, and in some noticed by Mr. Mitchell among the mirror-silverers of London.[959] Gilders, miners, and barometer-makers are all subject to the disease. Even those who undergo mercurial frictions may have it, according to Mérat; and M. Colson, who confirms this statement, quotes Swédiaur as another authority for it.[960] It is not merely long-continued exposure to mercurial preparations that causes the shaking palsy: a single strong exposure may be sufficient; and the same exposure may cause tremor in one and salivation in another. Professor Haidinger of Vienna some time ago mentioned to me an accident a barometer-maker of his acquaintance met with, which illustrates both of these statements. This man and one of his workmen were exposed one night during sleep to the vapours of mercury from a pot on a stove, in which a fire had been accidentally kindled. They were both most severely affected, the latter with salivation, which caused the loss of all his teeth, the former with shaking palsy, which lasted his whole life.

In regard to all such workmen, it is exceedingly probable that with proper care the evils of their trade may be materially diminished. This appears at least to be the result of the observations made long ago by Jussieu on the miners of Almaden in La Mancha. Most quicksilver mines are noted for great mortality among the workmen. But Jussieu maintains that the trade is not by any means so necessarily or so dreadfully unhealthy as is represented, or as it really is in some places. The free workmen at Almaden, he says, by taking care on leaving the mine to change their whole dress, particularly their shoes, preserved their health, and lived as long as other people; but the poor slaves, who could not afford a change of raiment, and who took their meals in the mine, generally without even washing their hands, were subject to swelling of the parotids, aphthous sore throat, salivation, pustular eruptions, and tremors.[961]

_Of the indirect effects of mercurial erethysm._—The last division of the secondary effects of mercury relates to its indirect action when concurring with other diseases or predispositions to disease.

Of these effects there are some of which the poison appears to be the chief, if not even the sole cause. Thus, during the symptomatic fever which precedes salivation there are sometimes remarked imitative inflammations, or coma, or affections of the heart, which go off as salivation is established.

Other effects require the distinct co-operation of collateral causes. Many inflammatory diseases, not easily excited in ordinary circumstances, arise readily from improper exposures during salivation, for example dropsy, pneumonia, phrenitis, iritis, erysipelas, and various chronic eruptions.

Other effects again require the co-operation of disease, such as sloughing gangrene supervening on ordinary ulcers during the action of mercury,—a not uncommon accident. This appears most likely to happen when the ulcers are constitutional.

Lastly, in conjunction with other diseased morbid actions, either going on at the same time, or immediately preceding mercurial erethysm, this poison is apt to occasion some modifications of disease which are rarely otherwise witnessed. Modifications of the kind have already been traced in the instances of lues venerea and scrofula; but there is reason to believe that the same singular property may also exist in relation to other constitutional disorders.

These observations conclude the inquiry into the symptoms caused in man by mercurial poisons generally. Returning now to its mode of action, we have to examine its relative effects through the different animal textures, and in its various chemical forms.

The result of the previous remarks as to its action on animals, it will be remembered, was, that its soluble preparations cause when swallowed corrosion of the stomach, and in whatever way it enters the body irritation of the stomach and rectum, inflammation of the lungs, depressed action and perhaps inflammation of the heart, oppression of the functions of the brain, and inflammation of the salivary glands. All of these effects have likewise been mentioned in the preceding sketch, as occurring in a greater or less degree in consequence of its operation on man.

Mercury acts as a poison on man in whatever way it is introduced into the body,—whether it be swallowed, or inhaled in the form of vapour, or applied to a wound, or even simply rubbed or placed on the sound skin. But the kind of action excited differs according to the channel by which it is introduced.

The most ordinary and dangerous cases of poisoning arise from the introduction of corrosive sublimate into the stomach. The poison then kills by corroding or inflaming the alimentary canal, or by causing salivation and its concomitants.

When applied to a wound or ulcer corrosive sublimate does not often occasion dangerous symptoms. Yet it is sometimes a hazardous remedy. It is not a convenient escharotic even in a concentrated state; for its escharotic action is not incompatible with its absorption; at all events it certainly sometimes acts constitutionally through the surface of wounds and ulcers, and the symptoms brought on in this way are generally violent. They are the symptoms of mercurial salivation, accompanied at times with well-marked inflammation of the alimentary canal. When applied to sores in a diluted state it has also been known to cause dangerous effects if too long persevered in. A case of the kind has been related by Mr. Robertson, an army-surgeon. After anointing an itchy eruption of the arms for seven days with a solution of corrosive sublimate containing five grains to the ounce, his patient was attacked with fever, inflammation of the stomach and bowels, and in two days more with violent salivation.[962] A case of the same nature has been related by Mr. Sutleffe.[963] His patient, a child, in consequence of having an eruption of the head washed with a solution of corrosive sublimate, was attacked with violent salivation, which proved fatal in a few days. Pibrac has recorded three fatal cases from the free application of corrosive sublimate to ulcerated surfaces. One of these proved fatal in five days, another in twenty-four hours, and a third during the night after the poison was applied. The symptoms generally indicated violent action on the alimentary canal.[964] In an instance mentioned by Degner, fatal in twenty-five days, there was also violent irritation of the stomach; but the chief affection was excessive swelling of the face and throat, together with profuse ptyalism.[965]

One of the readiest modes of bringing the system under the poisonous action of mercury is by introducing its preparations into the lungs. It appears from some experiments by Schlöpfer that the fluid preparations act rapidly through the lining membrane of the air-passages. Six grains of corrosive sublimate in solution will thus kill a rabbit in five minutes.[966] But the effects of mercury through this channel are much better exemplified when its preparations are inhaled in the form of vapour. Corrosive sublimate when incautiously sublimed in chemical experiments has been known to cause serious effects. Dr. Coldstream of Leith informs me, that while subliming about twenty-four grains of it with the blowpipe when a student, he and several of his fellow-apprentices were seized with painful constriction of the throat, several had headache, and one had sickness and vomiting. The phenomena produced by the various preparations of mercury in more violent cases, are sometimes protracted tremors,[967] sometimes severe ptyalism and tedious dysentery,[968] sometimes salivation and gangrene of the mouth ending fatally.[969] This last form was produced remarkably in a chimney-sweeper, after cleaning a gilder’s chimney, during which operation he felt a disagreeable sense of tightness in the throat.

Several extraordinary instances have happened of poisoning from long-continued inhalation of the vapours which arise from metallic mercury. That vapours do arise from metallic mercury of the ordinary temperature of the atmosphere has been fully proved by Mr. Faraday; who found, that when a bit of gold was suspended from the top of a phial, the bottom being covered with a little mercury, the gold soon became amalgamated.[970] The vapours thus discharged may produce the worst species of mercurialism, if they are diffused through an apartment insufficiently ventilated. One of the most striking examples known of the baneful effects of mercury thus gradually insinuated into the system, occurred in a well-known accident which befel the ships Triumph and Phipps. These vessels were carrying home in 1810 a large quantity of quicksilver saved from the wreck of a ship near Cadiz, when by some accident several of the bags were burst and the mercury spilled. On the voyage home the whole crews of both vessels were more or less severely salivated, two died, many were dangerously ill, all the copper articles on board became amalgamated, all the rats, mice, cockroaches, and other insects, as well as a canary-bird and several fowls, and all larger animals, such as cats, dogs, goats, and sheep were destroyed.[971]

The action of mercury is often violently excited when it is applied to the skin even not deprived of the cuticle. The effects of mercurial inunction form a well-known and satisfactory proof of this. Even without the aid of infriction, the soluble preparations of mercury will excite mercurial action by being put simply in contact with the skin. Thus it has been shown by a German physician, Dr. Guérard, that ptyalism may be induced by a warm bath of corrosive sublimate in the proportion of an ounce to 48 quarts of water, and that the effect commonly begins after the third bath with an interval of three days between them.[972] It is not so generally known that the more active preparations, such as corrosive sublimate or nitrate of mercury, may, like arsenic, cause through the sound skin effects almost as violent as through the alimentary canal. The following pointed illustration is related by Dr. Anderson. A gentleman affected with rheumatism, was persuaded by a friend to use a nostrum, which was nothing else than a solution of half a drachm of corrosive sublimate in an ounce of rum. This was rubbed on the affected part for several minutes before going to bed. Ere the friction was ended, he felt a sensation of heat in the part, to which, however, he paid little attention. But during the night he was attacked with pain in the stomach, sickness, and vomiting, and soon after with purging and tenesmus. In the morning Dr. Anderson found him very weak and vomiting incessantly. The arm up to the shoulder was prodigiously swelled, red, and blistered. Next day he complained of brassy taste and tenderness of the gums, and regular salivation soon succeeded.[973] Another case of much interest has been described by my colleague, Professor Syme, where a solution of the nitrate was rubbed by mistake upon the hip and thigh instead of camphorated oil. Intense pain immediately followed, and afterwards shivering; the urine was suppressed for five days, without any insensibility, and during its suppression urea was detected in the blood; ptyalism appeared on the third day, became very profuse, and was followed by exfoliation of the alveolar portion of the lower jaw, but recovery nevertheless slowly took place.[974]

The mere carrying of mercurial preparations for a length of time near the skin, though not in direct contact with it, may be sufficient to induce the peculiar effects of the poison, as the following example will show. A man applied to a German physician, Dr. Scheel, affected with violent salivation evidently mercurial which proved fatal, but which it was impossible to trace to its real cause till after death, when a little leathern bag containing a few drachms of mercury was found hanging at his breast; and it was then discovered that he had been in the practice of carrying this bag for six years as a protection against itch and vermin, and during that period had frequent occasion to renew the mercury.[975]

The effects of mercury as a poison differ with the chemical form in which it is introduced into the system.

In its metallic state it is probably inactive. This fact is a material one for the medical jurist to determine precisely; for running quicksilver has been given with a criminal intent. A case of the kind forms the subject of a medico-legal report in Pyl’s Repertory;[976] and another is mentioned in Klein’s Annals.[977]

It is well ascertained that large quantities of fluid mercury have been repeatedly swallowed, without any injury or peculiar effect having followed. In neither of the German cases now referred to was any bad effect produced; and it has proved equally harmless when given medicinally to remove obstruction in the intestines. Farther, M. Gaspard mentions in his paper quoted in a former page, that he has left large quantities shut up for many hours in the various cavities of the body in animals, without observing any other result than at times inflammation, which was evidently owing to the mere presence of a foreign body, and not to the action of an irritant poison.[978]

It has been already stated, however, that the vapours of metallic mercury, even at the temperature of the air, produce mercurialism when inhaled. But then, in all likelihood, some of the metal is oxidated before being inhaled. At least the chemist knows that the surface of a mercurial trough soon tarnishes, especially when the mercury is not pure.

But it may be said that the blue ointment, which is made with running quicksilver, will not act as a mercurial when rubbed upon the skin. Here too, however, some oxidation takes place in the making of the ointment. Mr. Donovan endeavoured to prove that some of the mercury is always oxidated;[979] and I have generally found a sufficient quantity of oxide to account for the effects.[980]

It has been farther said, in proof of the poisonous action of quicksilver in its metallic state,—that patients, who have taken it for obstructed bowels, have sometimes been salivated. This accident has, I believe, happened in a few instances where the mercury was retained long in the body. But such cases are undoubtedly very rare. Zwinger mentions the case of a man, who took four ounces for colic, and was seized in seven days with salivation.[981] Laborde relates the particulars of another instance where seven ounces taken in fourteen days excited ptyalism, ulceration of the mouth, and great feebleness of the limbs.[982] In the days of Dr. Dover, when the administration of large doses of fluid mercury was a fashionable practice for a variety of purposes, it was alleged to have even sometimes proved fatal; and the case of an actor is specially mentioned, to whom, when convalescent from ague, Dover gave mercury to the amount of two pounds in five days, and who at the close of that period was seized with headache, colic, restlessness, and costiveness, proving fatal in two days; and the whole lower intestines were found black and lined with minute metallic globules.[983] Perhaps then it must be admitted that fluid mercury is not altogether inactive, speaking medicolegally. But this admission is no argument in favour of the metal being physiologically a poison; because in the course of the cases referred to, a part is in all likelihood oxidated by the oxygen in the intestinal gases. It is said to have been taken in the dose of an ounce daily for nine months, without either good or harm resulting.[984]

The question regarding the poisonous qualities of running quicksilver was carefully investigated some years ago by the Berlin College of Physicians in a report on the case in Pyl’s Repertory.[985] They observe that the opinion of Pliny, Galen, Hippocrates, Dioscorides, and many of the earlier moderns, including even Zacchias, had led to the popular belief in the deadly properties of fluid mercury; but that this belief is erroneous; for many surgeons, and among the rest Ambrose Paré, had given without injury to their patients several pounds of it to cure obstructed bowels; and in 1515 the Margrave of Brandenburg, over-heated on his marriage night with love and wine, and rising to quench his thirst, drank by mistake a large draught of quicksilver without suffering any harm. Fallopius mentions that he had known instances of women swallowing pounds of mercury, for the purpose of procuring miscarriage, and who did not suffer any injury.[986]

The sulphurets of mercury, like the metal, are not possessed of any deleterious action on the animal body. Orfila found that half an ounce of the sulphuret, formed in a solution of corrosive sublimate by sulphuretted-hydrogen, and half an ounce or six drachms of cinnabar, had no effect whatever on dogs.[987] The sulphurets which have appeared injurious in the hands of Smith[988] and other previous experimentalists must therefore have been impure.

Of the compounds of mercury, the red-precipitate and Turbith-mineral act as irritants, besides possessing the property common to all mercurial compounds, of causing mercurial erethysm. But they are not escharotics, though generally termed such. That is, they do not chemically corrode the animal textures. The effects of red-precipitate have been variable. Mr. Allison relates the case of a girl who in a fit of jealousy swallowed thirty grains of it. Being immediately detected, an emetic was given, which operated freely, and subsequently the stomach-pump was used; but on neither occasion was any red powder brought away. She was attacked with burning pain in the stomach, which was removed by opium, and for a week she had a distaste for food, but no other symptom of consequence.[989] Mr. Brett has described a case, in which the symptoms were occasional vomiting, stupor, languid pulse, cold clamminess of the skin, afterwards severe cramps of the legs, tenderness of the abdomen, dysuria, and some purging, and on the third day ptyalism; but the patient recovered.[990] M. Devergie has given a case somewhat similar, but without any ptyalism having followed the irritant effects of the poison.[991] In 1840 I was consulted on the part of the Crown in the case of a girl, who, there was every reason to suppose, had been killed in twelve hours by red-precipitate. The symptoms towards the close were pain in the throat, inability to swallow, vomiting, and excessive prostration; extensive red patches were found on the villous coat of the stomach after death; and I detected mercury in the solid contents and likewise in the inner coat of the stomach. The case did not go to trial, because, although a man by whom she was pregnant came under some suspicion, it rather appeared that the deceased had herself swallowed the poison with the view of inducing miscarriage. Dr. Sobernheim has given the particulars of the case of a young man who died from swallowing an ounce of red-precipitate. He suffered for some hours from vomiting, diarrhœa, pain in the stomach, tenderness of the belly, and colic; next day he had no pain, but coldness, lividity, stiffness, and an imperceptible pulse; and he expired in thirty-three hours. The poison was found abundantly in the stomach and duodenum after death, and some grains of it rested upon little ulcers.[992] As to Turbith-mineral, two scruples will kill a cat in four hours and a half; and several instances of violent and even fatal poisoning with it are mentioned by the older modern authors.[993]

The white precipitate or chloride of mercury and ammonia is probably also irritant, though inferior in power to the preparations just mentioned. Two scruples given to a dog occasion vomiting, pain, and some diarrhœa; and cases are recorded of death in the human subject from less doses.[994] But there are no recent facts as to the activity of this compound, and the older cases, which would assign to it very great energy, are open to the objection that this preparation was in former times often impure.

The bichloride or corrosive sublimate is a powerful corrosive or irritant, according to the dose and state of concentration; and it also excites mercurial erethysm in a violent degree. The nitrates too are corrosive, and not inferior in activity to the bichloride, as may be inferred from Dr. Bigsby’s case, noticed at page 314.

The bicyanide or prussiate of mercury, from the researches of Ollivier, and an interesting case he has published of poisoning with it in the human subject, appears to resemble corrosive sublimate closely in all its effects, except that it does not corrode chemically. Twenty-three grains and a half proved fatal in nine days.[995] M. Thibert has described a case in which ten grains caused death in the same period of time.[996] The symptoms in both instances were those of severe irritation of the stomach, extensive inflammation of the organs in the mouth, and suppression of urine; and in Thibert’s case a small quantity of albuminous fluid was discharged from the bladder instead of urine.

The protochloride or calomel, and probably also the protoxide, are the most manageable of the preparations of mercury for inducing ptyalism. Calomel is also an irritant; that is, it causes irritation and inflammation in the alimentary canal when swallowed. This part of its properties as a poison will require a word or two of explanation.

Calomel is universally employed as a laxative, but to secure this effect being produced it is commonly combined with other purgatives. When given alone a few grains will in some constitutions induce a violent hypercatharsis; and larger, but still moderate, doses have with most people such a tendency to cause severe griping and diarrhœa as to have led to the practice of combining it with opium when the object is to salivate. These considerations clearly establish that calomel, in a moderate dose of five or ten grains, is an irritant.

It farther appears that in larger doses it is said to have occasionally produced very violent effects, nay, even death itself, by its irritant operation. Hoffmann has mentioned two instances where fifteen grains of calomel proved fatal to boys between the ages of twelve and fifteen. One of them had vomiting, tremors of the hands and feet, restlessness and anxiety, and died on the sixth day. The other, he merely mentions, died after suffering from extreme anxiety and black vomiting.[997] Another fatal case has been related by Ledelius in the German Ephemerides, which was caused by a dose of half an ounce taken accidentally. Vomiting soon ensued, and a sense of acridity in the throat; then profuse diarrhœa to the extent of twenty evacuations in the day; next excessive prostration of strength and torpor of the external senses; and death followed in little more than twenty-four hours.[998] Wibmer quotes Vigetius, an author of the beginning of last century, for a similar case, likewise fatal, which was occasioned by half an ounce,—also Hellweg, a writer of the previous century, for the case of a physician, who took an ordinary medicinal dose by way of experiment, and died in five hours under all the symptoms of violent irritant poisoning.[999]

These observations being kept in view, what explanation will the toxicologist give of the effects which in modern times have been ascribed to large doses of calomel? It was stated not many years ago by several East India surgeons, apparently with the universal assent of their brethren in later times, that this drug in the dose of a scruple administered even several times a day, is not only not an irritant, but even on the contrary a sedative;[1000] and that in some diseases, for example yellow fever, it has been given in the dose of five, ten, or twenty grains, four or six times a day, till several hundred grains were accumulated in the body, yet without causing hypercatharsis, nay, with the effect of checking the irritation which gives rise to black vomit in yellow fever, and to the vomiting and diarrhœa observed in the cholera of the East. It is quite impossible for a European physician to doubt these statements; for all practitioners in hot climates concur in them, and now that analogous practices have been transferred to Britain, repeated opportunities have occurred for establishing the fidelity of the original reporters. Some American physicians, advancing beyond the Hindostan treatment, have since given calomel in bilious fever in the dose of forty grains, one drachm, two drachms, and even three drachms, repeatedly in the course of twenty-four hours for several days together,—and with similar phenomena. In one instance 840 grains were given in the course of eight days in these enormous doses. The largest dose was three drachms; and it was followed by only one copious evacuation, and that not till after the use of an injection.[1001] This practice appears not to have been altogether unknown in former times. Ledelius, the author formerly quoted, states, that he had been accustomed to give doses of a scruple, and that Zwölffer even gave a drachm in one dose.[1002]

It must be also added, that while the facts quoted above from Hoffmann, Ledelius, and others assign to single large doses a powerful and dangerous irritant action, very different results have been occasionally observed in recent times where even so large a quantity as one or two ounces had been taken. Thus, in the case of a lady mentioned by Wibmer, who took by mistake the enormous quantity of fourteen drachms, although acute pain in the belly ensued, together with vomiting and purging, these symptoms were speedily subdued by oleaginous demulcents; and after a smart salivation, she recovered entirely in six weeks.[1003] Another case has been related by Mr. H. P. Robarts, where an ounce was swallowed by a young lady by mistake for magnesia, with no other effect than nausea at first, rather severe griping and slight tenderness of the belly afterwards, and subsequently languor, headache and indigestion; yet the powder was retained two hours.[1004]

It is impossible in the present place to enter into the physiological action of calomel as a remedy; but every one must be satisfied that, with all which has been already written, much still remains to be done before the facts now mentioned can be explained satisfactorily. Can the violent effects described by Hoffmann, Ledelius and Hellweg have arisen from the calomel having been imperfectly prepared and adulterated with a little corrosive sublimate? Or may they be explained by reference to the fact, that the presence of hydrochlorates in solution, particularly hydrochlorate of ammonia, tends to convert calomel into corrosive sublimate.[1005] Mr. Alfred Taylor has made some experiments, to show that the latter explanation will not suffice.[1006]

Meanwhile, taking the facts as they stand, it is plain that great caution must be used in ascribing violent irritant properties generally, or even symptoms of irritant poisoning in a particular case, to large doses of calomel.

With the view of illustrating the importance of the preceding observations, it may be useful to mention here the heads of a case already briefly alluded to for another purpose, the trial of William Paterson for murder (319).[1007] His wife during the month previous to her death had two attacks of diarrhœa, with an interval of a fortnight between them. On the second occasion it became profuse and exhausting, but without any material pain or considerable vomiting; looseness of the teeth and salivation ensued, and she died in nine days. On examination of the body, the anus was found excoriated, the whole intestines checkered with dark patches, and the stomach red, ulcerated, and spotted with black, warty excrescences; but the late Dr. Cleghorn of Glasgow could not detect any poison by chemical analysis. It was proved that the prisoner, besides procuring, a few months before his wife’s death, a variety of poisons, such as hydrochloric acid, cantharides, and arsenic, had also on different occasions during her last illness purchased in a suspicious manner four doses of calomel varying from 30 to 60 grains each. Among the various ways in which he was charged with having poisoned the deceased, that which was best borne out by the general as well as medical facts consisted in his taking advantage of an existing inflammation of the mucous membrane of the bowels,—whether arising from a natural cause or from poison it was in this view of the case immaterial to inquire,—and keeping up and aggravating the inflammation by purposely administering at intervals large doses of calomel. On the trial Dr. Cleghorn and other witnesses gave their opinion that the doses purchased by the prisoner, if administered, would cause the symptoms and morbid appearances observed in the case. On the other hand, the late Dr. Gordon deposed to the effect, that all the symptoms of the case might arise under the operation of natural disease, and that such doses of calomel were by no means necessarily injurious; the late Mr. John Bell deposed, that it had even been given in much larger doses without injury; and the profession are now well aware, though not at the time of this trial, that in the very malady alleged by the prisoner to have carried off the deceased, namely dysentery, the administration of calomel in repeated large doses is accounted by many a proper method of cure. The doses purchased by the prisoner were considerably larger, it is true. But there was not any evidence of his having administered his purchases in single doses as he got them; and even though there had been evidence to that effect, it would not remove altogether the difficulty of deciding the question, as to the irritating action of calomel, on which the issue of the trial in one view of the case chiefly depended.

It is probable that all the compounds formed by corrosive sublimate with animal and vegetable substances are feebly poisonous, or at least very much inferior in activity to corrosive sublimate itself. This has been shown by Orfila to be the case with the compound formed by albumen. Sixty grains of this compound, being equivalent to nearly five grains of corrosive sublimate, produced no bad effect whatever on a dog or a rabbit.[1008] The same has been satisfactorily proved by Taddei as to the compound formed by gluten. Twelve grains of corrosive sublimate decomposed by his emulsion of gluten had no effect whatever on a dog.[1009] It is important to remark, however, that if there be an excess of the decomposing principle, so that the precipitate is party redissolved, the irritant action of the corrosive sublimate is not so much reduced, though it is still certainly diminished. Orfila has settled this point in regard to albumen.[1010] The power of producing mercurial erethysm is possessed by all mercurial compounds whatever, and among the rest by the compounds now under consideration.[1011]

The present section may now be concluded with a few remarks on the strength of the evidence derived from the symptoms which are produced by the compounds of mercury.

If the medical jurist should meet with a case of sudden death like that of the animals experimented on by Sir B. Brodie, the symptoms alone could not constitute any evidence of poisoning with corrosive sublimate. All he could say would be that this variety of poisoning was possible, but that various natural diseases might have the same effect. This feebleness in the evidence from symptoms, however, is of little moment; because the dose must be great to cause such symptoms, and little can be vomited before death; so that the poison will be certainly found in the stomach.

Should the patient die under symptoms of general irritation in the alimentary canal, poisoning may be suspected. But it would be impossible to derive from them more than presumptive evidence. The suspicion must become strong, however, if the ordinary signs of irritation in the alimentary canal are attended with the discharge of blood upwards and downwards. And the presumption will, I apprehend, approach very near to certainty,—at least of the administration of some active irritant poison,—if, at the moment of swallowing a suspected article, and but a short time before the symptoms of irritation began in the stomach and bowels, the patient should have remarked a strong, acrid, metallic taste, and constriction or burning in the throat.

When upon all these symptoms salivation is superinduced, the evidence of poisoning with corrosive sublimate or some other soluble salt of mercury is almost unequivocal. That is, if, after something has been taken which tasted acrid, and caused an immediate sense of heat, pricking, or tightness in the throat, the characteristic signs of poisoning with the irritants make their appearance in the usual time, and are soon after accompanied or followed by true mercurial salivation,—it may be safely inferred that some soluble compound of mercury has been taken. Before drawing this inference, however, it will be necessary to determine with precision all the classes of symptoms, more particularly the nature of the salivation. It should also be remembered that salivation may accompany or follow the symptoms of inflammation in the stomach, in consequence of calomel having been used as a remedy. But if proper attention be paid to the fallacies in the way of judgment, I conceive that an opinion on the question of poisoning with corrosive sublimate may be sometimes rested on the symptoms alone. This is another exception to the rule laid down by most modern toxicologists and medical jurists respecting the validity of the evidence of poisoning from symptoms.

For a good example of the practical application of these precepts, the reader may consult the trial of Mr. Hodgson, for attempting to poison his wife. In the instance which gave rise to the trial in question, a violent burning sensation in the throat was felt during the act of swallowing some pills; in the course of ten minutes violent vomiting ensued, afterwards severe burning pain along the whole course of the gullet down to the stomach, next morning diarrhœa, and on the third day ptyalism. There were many other points of medical evidence which left no doubt that corrosive sublimate was swallowed in the pills. But even the history of the symptoms alone would have led to that inference.[1012]

SECTION III.—_Of the Morbid Appearances caused by Mercury._

The morbid appearances observed in the bodies of persons killed by corrosive sublimate will not require many details; since most of the remarks formerly made under the head of the pathology of the irritants generally, and of arsenic in particular, apply with equal force to the present species of poisoning. Still there are some peculiarities deserving of notice, which arise from the greater solubility or stronger irritant action of corrosive sublimate.

The mouth and throat are more frequently affected than by arsenic; and a remarkable appearance sometimes observed, and not excited, so far as I know, by arsenic, is shrivelling of the tongue, with great enlargement of the papillæ at its root.[1013]

The disorder of the alimentary canal is also usually more general, and reaches a greater height before death takes place. Sometimes the irritation and organic injury are confined to the stomach;[1014] but more commonly the throat, stomach, gullet, rectum, nay, even also the colon, are affected. The black or melanotic extravasation into the mucous membrane of the stomach, which has been already several times described as a common effect of the more violent irritants, is also produced by corrosive sublimate. In Devergie’s case and in that of Dr. Venables it was present in a very great degree.[1015]

The coats of the stomach, and also those of the intestines, more particularly the colon and rectum, have frequently been found destroyed. So far as I have been able to ascertain, two kinds of destruction of the coats may be met with,—corrosion and ulceration.

The first is the result of chemical decomposition of the tissues. This kind is evidently to be looked for only when the quantity has been considerable and the dose concentrated. Nay even then it is rare. For on account of the solubility of corrosive sublimate, the facility with which it is decomposed by the secretions or accidental contents of the stomach, and the violence and frequency of the vomiting, this poison is peculiarly liable to be prevented from exerting its corrosive action on the membranes. Hence it is that proper chemical corrosion of the coats of the stomach is seldom witnessed in man.

The appearance of this corrosion differs according to the rapidity of the poisoning. In very rapid cases, for example in animals which have survived only twenty-five minutes, the villous coat has a dark gray appearance, without any sign of vital reaction.[1016] But this variety has never been witnessed in man, in whom the action has been hitherto much less rapid. In the most rapid cases, such as that of Dr. Bigsby, which terminated in two hours and a half (314), or those related by Mr. Valentine, of which one ended fatally in eleven and another in twenty-four hours, the corrosion was black, like the charring of “leather with a red-hot coal, and the rest of the stomach scarlet-red or deep rose-red;—showing that inflammation had set in.” In the former of these two cases the corrosion was as big as a half-crown, in the latter three inches in diameter. In a third case, where the patient lived thirty-one hours, the stomach was perforated.[1017] In the case described by Dr. Venables, and formerly alluded to, where life was prolonged for eight days, there was a patch on the under surface of the stomach as large as two crown-pieces, hard, elevated, and of a very dark olive or almost black colour, besides very general erosion of the villous coat.[1018] In all these cases the disintegrated spot was probably situated where the poison first chiefly lodged.

The corrosion caused by mercury, if examined before the slough is thrown off, will be found to possess an important peculiarity: the disorganized tissue yields mercury by chemical analysis. Professor Taddei repeatedly obtained the metal from the membranes of animals which he had poisoned with corrosive sublimate.[1019] It is probable that mercury may be thus detected although death may not have taken place for some time after the poison was swallowed. For the slough was found adhering in one of Mr. Valentine’s cases, where life was prolonged for seventy hours; and it was not entirely removed even in eight days in one of the cases described by Dr. Venables.

Although, however, it is sometimes possible to find the poison in the stomach, the medical jurist must not perhaps expect to find it so often in the present instance as in that of poisoning with arsenic. For on account of its greater solubility corrosive sublimate cannot adhere with such obstinacy to the villous coat, and is therefore more subject to be discharged by vomiting. Nevertheless, the insoluble compound formed by antidotes may adhere to the coats like arsenic, and so resist the tendency of vomiting to displace them. In Devergie’s case, notwithstanding twenty-three hours of incessant vomiting, although no poison could be detected in the fluid contents of the stomach, it was distinctly found in small whitish masses that lay between the folds of the rugæ.[1020]

It may be here farther observed that corrosive sublimate, as well as other salts of mercury, may undergo in the alimentary canal after death the same change which is produced in arsenic from the gradual action of hydrosulphuric acid gas. It may be converted into the sulphuret. I am not acquainted indeed with any actual instance of such conversion; but that it may occur we can scarcely doubt, not merely from theoretical considerations, but likewise because Orfila met with an instance where calomel taken daily in a case of gastro-cephalitis was discharged by stool in the form of a black sulphuret.[1021]

Another important consideration is, that corrosive sublimate may be decomposed and reduced to the metallic state by the admixture of various substances either given at the same time or subsequently, and the longer the inspection is delayed, the more complete will be the decomposition which is accomplished. Iron, zinc, and other metals are the most active of these substances.[1022]

The other forms of destruction of the coats of the alimentary canal is common ulceration, either such from the beginning, or what was originally corrosion converted into an ulcer in consequence of the disorganized spot being thrown off by sloughing.

I have seen this appearance to an enormous extent in the great intestines of a man who survived nine days. Numerous large, black, gangrenous ulcers, just like those observed in bad cases of dysentery, were scattered over the whole colon and rectum. In this instance, which occurred to the late Dr. Shortt, the stomach was also ulcerated, but the small intestines were not.

Sometimes the ulceration seems to be a variety of softening of the mucous tissue, as in a case described by Dr. Alexander Wood of this city, which proved fatal in fourteen days, and in which the stomach, cæcum, and ascending colon presented round, softened, greenish spots about the size of a sixpence, and accompanied in the stomach with a tendency to detaching of the membrane in the form of a slough.[1023]

The destruction of the villous coat of the stomach occasioned by corrosive sublimate and other soluble salts of mercury may be distinguished from spontaneous gelatinization by one of two characters. If the slough remains attached, mercury will be detected in it: if separation has taken place, the ulcer exposed presents surrounding redness and other signs of reaction.[1024]

All the other effects of inflammation may be produced by corrosive sublimate, as by arsenic and other irritants. More frequently here than in the case of arsenic peritonæal inflammation is met with. In Devergie’s case the external surface of the stomach along both its curvatures presented the appearance of red points on a violet ground. In Mr. Valentine’s cases there was much minute vascularity, not only of the outside of the stomach but also of the whole peritonæum lining the viscera and inside of the abdomen; and there was even some serous effusion into the cavity. In Dr. Venables’s case the peritonæal coat of the stomach was highly vascular and inflamed, and the omentum also injected.

The urinary organs, and particularly the kidneys, are often much inflamed by poisoning with corrosive sublimate. Dr. Henry has related a case in which this poison proved fatal on the ninth day, and where the left kidney was found to contain an abscess.[1025] In all of Mr. Valentine’s cases the kidneys were inflamed, and the bladder excessively contracted, so as not to exceed the size of a walnut. In Ollivier’s case, caused by the cyanide of mercury, the scrotum was gorged and black, the penis erected, and the kidneys a third larger than natural. In the case described by Dr. Venables both kidneys, but especially the left, were large, flaccid, and vascular, the ureters turgid and purple, and the bladder contracted, empty, and red internally.

Orfila has observed that the internal membrane of the heart is sometimes inflamed and checkered with brownish-black spots. Some remarks have been already made on the light in which this appearance ought to be viewed by the pathologist (p. 271).

Whatever may be the real state of the fact as to the alleged power of arsenic to preserve from decay the bodies of those poisoned with it, all authors agree that corrosive sublimate possesses no such property. Yet it is well known to be a good antiseptic, when applied topically. The experiments of Klanck, noticed under the head of Arsenic, prove that corrosive sublimate at all events does not retard putrefaction in the bodies of those poisoned with it; and Augustin in his analysis of Klanck’s researches infers that it even promotes decay.[1026] I have met with one example in the human subject which seems to confirm Augustin’s opinion. In the case formerly quoted from the Medical and Physical Journal, which was fatal in four days, the relater found the body forty-two hours after death so putrid, though in the month of January, that the examination of it was very unpleasant, the belly being black, and a very offensive odour being exhaled.[1027] Little importance, however, can be attached to a solitary case; for on the contrary Sallin relates a case where the body of a man supposed to have been poisoned with corrosive sublimate was found not decayed, but imperfectly mummified, after sixty-seven days.[1028]

It is unnecessary to detail the proofs to be found in the dead body of mercurial salivation having existed during life. They are of course to be looked for in the mouth, and in the adjoining organs. We must not, however, expect to see much appearance of disease in the salivary glands; for according to Cruveilhier, in persons who die of mercurial salivation these glands do not present any trace of inflammation themselves, but merely serous effusion into the cellular tissue around them.[1029]

Professor Orfila has made some useful experiments as to the effects of corrosive sublimate on dead intestine, which it may be proper to notice in a few words. When applied in the form of powder to the rectum of an animal newly killed, the part with which it is in contact becomes wrinkled, and as it were granulated, harder than natural, and of alabaster whiteness, intermingled with rose-red streaks, apparently the ramifications of vessels. When the membrane is stretched upon the finger, the wrinkling disappears. The muscular coat is of a snow-white colour, and even the serous coat is white, opaque, and thickened. The parts not in contact with the powder retain their natural appearance, and the line of demarcation between the affected and unaffected portions is abrupt. If the powder is not applied till twenty-four hours after death, the parts it touches become thick, white, and hard; but no red lines are visible. It is easy to draw the distinction between these appearances and the effects of corrosive sublimate during life.

Little need be said of the force of the evidence of poisoning with corrosive sublimate, derived from the morbid appearances. If the gullet, stomach, and colon be all inflamed and ulcerated, and these injuries have taken place during a short illness, the presumption in favour of some form of irritant poisoning will be strong. And the presumption of poisoning with corrosive sublimate will be strong, if the usual marks of salivation are also found in the mouth and throat. But such evidence can never amount to more than a strong presumption or probability.

SECTION IV.—_Of the Treatment of Poisoning with Mercury._

The treatment of poisoning by the compounds of mercury may be referred to two heads,—that which is required when irritation of the alimentary canal is the prominent disorder, and that which is designed to remove mercurial salivation.

Irritation and inflammation of the alimentary canal are to be treated nearly in the same way as when arsenic has been the poison swallowed. In the instance of corrosive sublimate we also possess a convenient and effectual antidote.

Several substances may be used as antidotes; but those which have hitherto been most employed are albumen and gluten.

It has been already hinted that albumen, in the form of white of eggs beat up with water, impairs or destroys the corrosive properties of bichloride of mercury, by decomposing it and producing an insoluble mercurial compound. For this discovery and the establishment of albumen as an antidote, medicine is indebted to Professor Orfila. He has related many satisfactory experiments in proof of its virtues. The following will serve as an example of the whole. Twelve grains of corrosive sublimate were given to a little dog, and allowed to act for eight minutes, so that its usual effects might fairly begin before the antidote was administered. White of eight eggs was then given; after several fits of vomiting the animal became apparently free from pain; and in five days it was quite well.[1030] According to Peschier the white of one egg is required to render four grains of the poison innocuous.[1031] The experiments of the Parisian toxicologist have been repeated and confirmed by others and particularly by Schloepfer; who found that when a dose was given to a rabbit sufficient to kill it in seven minutes if allowed to act uncontrolled, the administration of albumen, just as the signs of uneasiness appeared, prevented every serious symptom.[1032] Dr. Samuel Wright has found that if the administration of albumen is followed up by giving some astringent decoction or infusion, the beneficial effects are more complete, because the compound formed is less soluble in an excess of albumen.[1033]

The virtues of albumen have also been tried in the human subject with equally favourable results. The recovery of the patient, whose case was quoted formerly (p. 312), from Orfila’s Toxicology, seems to have been owing in great measure to this remedy. In the Medical Repository another case is related, in which it Was also very serviceable.[1034] A third very apposite example of its good effects is related by Dr. Lendrick. His patient had taken about half a drachm of corrosive sublimate, and was attacked with most of the usual symptoms, except vomiting. White of eggs was administered a considerable time afterwards, the beneficial effects of which were instantaneous and well-marked; and the patient recovered.[1035] A few years ago Orfila’s discovery was the means of saving the life of M. Thenard the chemist. While at lecture, this gentleman inadvertently swallowed, instead of water, a mouthful of a concentrated solution of corrosive sublimate; but having immediately perceived the fatal error, he sent for white of eggs, which he was fortunate enough to procure in five minutes. Although at this time he had not vomited, he suffered no material harm. Without the prompt use of the albumen, he would almost infallibly have perished.[1036]

Albumen is chiefly useful in the early stage of poisoning with corrosive sublimate, and is particularly called for when vomiting does not take place. But it farther appears to be an excellent demulcent in the advanced stages.

On a previous occasion, mention was made of a few of the facts brought forward by Professor Taddei to prove the virtues of the gluten of wheat as an antidote for poisoning with corrosive sublimate [297, 336], so that nothing more need be said on the subject in the present place. As it is difficult to bring the whole of a fluid containing corrosive sublimate into speedy contact with pulverized gluten, which when put into water becomes agglutinated into a mass, the discoverer of this antidote proposes to give it in the form of emulsion with soft soap. This is made by mixing, partly in a mortar and partly with the hand, five or six parts of fresh gluten with fifty parts of a solution of soft soap. And in order to have a store always at hand, this emulsion, after standing and being frequently stirred for twenty-four hours, is to be evaporated to dryness in shallow vessels, and reduced to powder. The powder may be converted into a frothy emulsion in a few minutes.[1037] Taddei made use of this powder with complete success in the case of a man who had swallowed seven grains of corrosive sublimate by mistake for calomel. Violent symptoms followed the taking of the poison; but they were immediately assuaged by the administration of the antidote; and the person soon got quite well.[1038] It is probable that wheat flour will prove an effectual antidote by reason of the gluten it contains. On agitating for a few seconds a solution of twelve grains of corrosive sublimate along with three ounces of a strong emulsion of flour, and immediately filtering,—I find that ammonia and carbonate of potass have little or no effect, that hydriodate of potass occasions a yellow precipitate, and that the acrid, astringent taste of the solution is removed; whence it may be inferred, that the corrosive sublimate is all decomposed, that little mercury remains in solution, and that what does remain is in the form of a chloride of mercury and gluten.

When neither albumen nor gluten is at hand, milk is a convenient antidote of the same kind.

Iron filings would appear to be also a good antidote. MM. Milne-Edwards and Dumas have found that when they were administered in the dose of an ounce to animals after twelve or eighteen grains of corrosive sublimate had remained long enough in the stomach for the symptoms to begin, the animals recovered from the effects of the poison, and died only some days afterwards of the effects of tying the gullet, which operation was necessary to prevent them vomiting. The iron obviously acts by reducing the corrosive sublimate to the metallic state.[1039]

Meconic acid, the peculiar acid of opium, which will be described under the head of that poison, is also probably a good antidote. Pettenkoffer correctly remarks that this acid has a great tendency to form very insoluble salts with the metallic oxides, particularly with the deutoxides, and above all when the acid is previously in union with a base which constitutes a soluble salt.[1040] On this account it must be a good antidote. Pettenkoffer adds, that the precipitating action of the meconates is the reason why “the operation of corrosive sublimate on the animal body is almost entirely prevented by opium.” Opium, however, cannot be safely used in such quantity as to decompose all the corrosive sublimate in a case of poisoning; for I find that an infusion of thirty-three grains is required to precipitate all which can be thrown down from a solution of five grains of the mercurial salt. I am not aware of any instances on record where poisoning with corrosive sublimate has been prevented or cured by opium given so as to decompose the salt; but a very remarkable case will be related under the head of Compound Poisoning, where the phenomena of its action were masked and altered in a singular manner. There is little doubt that the alkaline meconates must prove valuable antidotes for corrosive sublimate. At present an effectual barrier to their employment is their rarity; but they might be rendered more accessible, as a great quantity of meconate of lime, which is at present put to no use, is formed in the manufacture of muriate of morphia; and meconate of potass may easily be prepared in sufficient quantity from the meconate of lime.

It has been alleged by Dr. Buckler of Baltimore, that a mixture of gold-dust and iron filings is an effectual antidote; but Orfila denies this statement; and the fact if true would be unimportant, on account of the improbability of the materials being ever at hand in practice.[1041]

M. Mialhe suggested not long ago as an antidote the proto-sulphuret of iron prepared by decomposing sulphate of protoxide of iron by hydrosulphate of ammonia; and Orfila found that it is a perfect chemical antidote, which altogether prevents the poisonous action of corrosive sublimate, if administered to animals either before or immediately after the poison; but he further ascertained that the lapse of ten minutes was sufficient to render it of no use.[1042] It is difficult, however, to perceive why in this respect it should differ from white of egg or any other chemical antidote.

As to the old antidotes for poisoning with corrosive sublimate, such as the alkaline carbonates, the alkaline hydrosulphates, cinchona, mercury, charcoal,—Orfila has given them all a fair trial, and found them all inefficacious. It would appear, however, from a case related in a late American journal, that frequent doses of charcoal powder have much effect in soothing the bowels and allaying the inflammation after the poison is evacuated.[1043]

The treatment of mercurial salivation consists in exposure to a cool pure air, nourishing diet, and purgatives, if the intestinal canal is not already irritated. In some of the inflammatory affections it induces, venesection is required; in others it is hurtful. In some complaints induced by mercury, as in iritis, the poison appears to be its own antidote; for nothing checks the inflammation so soon and so certainly as mercurial salivation.

Dr. Finlay of the United States proposed to check mercurial salivation by small doses of tartar emetic frequently repeated, so as to act on the skin;[1044] and Mr. Daniell has recommended large doses of the acetate of lead as an effectual antidote for the same purpose.[1045] I have tried both of these plans several times with apparent success. In one instance particularly, where a severe salivation was threatened by the administration of six grains of calomel in three doses, and where profuse salivation, ulceration of the tongue and swelling of the face actually did commence with violence, the mercurial affection after a few days rapidly receded under the use of large doses of acetate of lead.—Dr. Klose, a German physician, says he has found iodine to possess the property of arresting the effects of mercury on the mouth.[1046] The iodide of potassium is generally acknowledged to be one of the best remedies for eradicating the constitutional infirmities left in many by severe courses of mercury.

A great deal might be said on the treatment of the secondary effects of poisoning with mercury. But a thorough investigation of the subject would lead to such details as would be inconsistent with the other objects of this work.