Part 25

The first use of carbonate of magnesia medicinally was in the form of a secret medicine which must have acquired much popularity in the beginning of the eighteenth century. It was prepared, says Bergmann, by a regular canon at Rome, sold under the title of the powder of the Count of Palma, and credited with almost universal virtues. The method of preparation was rigidly concealed, but it evidently attracted the attention of chemists and physicians, for it appears that in 1707 Valentini published a process by which a similar product could be obtained from the mother liquor of “nitre” (soda) by calcination. In 1709 Slevogt obtained a powder exactly resembling it by precipitating magnesia from a solution of the sulphate by potash. Lancisi reported on it in 1717, and in 1722 Hoffmann went near to explaining the distinction between the several earthy salts, which in his time were all regarded as calcareous.

Hoffmann’s process to obtain the powder was to add a solution of carbonate of potash to the mother liquor from which rough nitre had been obtained (solution of chloride of magnesium), and collect the precipitate. This being yielded by two clear solutions gave to the carbonate of magnesia precipitated the name of Miraculum Chemicum.

Magnesia was the name of a district in Thessaly, and of two cities in Asia Minor. The Greek “magnesia lithos,” magnesian stone, has been frequently applied to the lodestone, but this can hardly have been correct, as the magnesian stone was described as white and shining like silver. Liddell and Scott think talc was more probably the substance. The alchemists sometimes mention a magnesia, but the name seems to have been a very elastic one with them. The Historical English Dictionary quotes the following reference to the word from “Norton Ord. Alch.,” 1477:--“Another stone you must have ... a stone glittering with perspicuitie ... the price of an ounce conveniently is Twenty Shillings. Her name is Magnetia. Few people her knows.”

Paracelsus uses the term in the sense of an amalgam. He writes of the Magnesia of Gold. In Pomet’s “History of Drugs,” 1712, magnesia meant manganese. Hoffmann, 1722, first applied the name to oxide of magnesia, adapting it from the medical Latin term, magnes carneus, flesh magnet, because it adheres so strongly to the lips, the fancy being that it attracts the flesh as the lodestone attracts iron.

Hoffmann’s observations on magnesia and its salts, which were published in the first quarter of the eighteenth century, were very intelligent, and undoubtedly it was he who first distinguished magnesia from chalk. He says “A number of springs, among which I may mention Eger, Elster, Schwalbach, and Wilding, contain a neutral salt which has not yet received a name, and which is almost unknown. I have also found it in the waters of Hornhausen which owe to this salt their aperient and diuretic properties. Authors commonly call it nitre; but it has nothing in common with nitre. It is not inflammable, its crystallising form is entirely different, and it does not yield aqua fortis. It is a neutral salt similar to the arcanum duplicatum (sulphate of potash), bitter in taste, and producing on the tongue a sensation of cold.” He further states that the salt in question appears to proceed from the combination of sulphuric acid with a calcareous earth of alkaline nature. The combination “is effected in the bosom of the earth.” In another of his works Hoffmann distinguishes the magnesian salt from one of lime, showing particularly that the latter was but slightly soluble and had scarcely any taste. Crabs’ eyes and egg shells he notes combine with sulphuric acid and form salts with no taste. The sulphate of this earth (Epsom salt) he found had a strong bitter taste.

The true character of magnesia and its salts was not clearly understood until Joseph Black unravelled the complications of the alkaline salts by his historic investigation, which became one of the most noted epochs of chemistry by its incidental revelation of the combination of the caustic alkalies with what Black termed “fixed air,” subsequently named carbonic acid gas by Lavoisier in 1784. When Black was studying medicine at Edinburgh a lively controversy was in progress in medical circles on the mode of action of the lithontriptic medicines which had lately been introduced. Drs. Whytt and Aston, both university professors, were the leaders in this dispute. Whytt held that lime water made from oyster shells was more effective for dissolving calculi in the bladder than lime water prepared from ordinary calcareous stone. Alston insisted that the latter was preferable. Black was interested, and his experiments convinced him of the scientific importance of his discoveries. He postponed taking his degree for some time in order to be sure of his facts. His graduation thesis, which was dated June 11, 1754, was entitled “De humore acide cibis orto et magnesia alba.” His full treatise, “Experiments upon magnesia alba, quicklime, and some other alkaline substances,” was published in 1756. It had been previously believed that the process of calcining certain alkaline salts whereby caustic alkalies were produced was explained by the combination with the salt of an acrid principle derived from the fire. Now it was shown that something was lost in the process; that the calcined alkali weighed less than the salt experimented with. The something expelled Black proved was an air, and an air different from that of the atmosphere, which was generally supposed to be the one air of the universe. He identified it with the “gas sylvestre” of Van Helmont, and named it “fixed air.” Magnesia alba first appeared in the London Pharmacopœia of 1787 under that name.

The oxide of magnesia was believed to be an elementary substance until Sir Humphry Davy separated the metal from the earth by his electrolytic method in the presence of mercury. By this means he obtained an amalgam, and by oxidising this he reproduced magnesia and left the mercury free, thus proving that the earth was an oxide of a metal. In 1830 Bussy isolated the magnesium by heating in a glass tube some potassium covered with fragments of chloride of magnesium, and washing away the chloride of potassium formed. Magnesium in small globules was left in the tube. The metal is now prepared on an industrial scale either by electrolysis, or by fusing fluor-spar with sodium. At present the uses of magnesium and of its derivatives are infinitesimal in comparison with the vast quantities available in deposits, as in dolomite, and in the sea.

NITRE

among the ancient Greeks and Romans generally meant carbonate of soda, sometimes carbonate of potash. The Arab chemists, however, clearly described nitrate of potash. In the works attributed to Geber and Marcus Græcus, especially, its characters are represented. Raymond Lully, in the thirteenth century, mentions sal nitri, and evidently alludes to saltpetre, and Roger Bacon always meant nitrate of potash when he wrote of nitre. It was not, however, until the seventeenth century that the term acquired the definite meaning which we attach to it.

At the beginning of that century there was much discussion as to the formation of nitre, as it had been held that the acid which combined with the alkali was ready formed in the atmosphere. Glauber was the first to argue that vegetables formed saltpetre from the soil. Stahl taught that the acid constituent of nitre was vitriolic acid combined with phlogiston emanating from putrefying vegetable matter.

After gunpowder had become a prime necessity of life, saltpetre bounded upwards in the estimation of kings and statesmen. In France in 1540 an Edict was issued commissioning officials called “salpêtriers” in all districts who were authorised to seek for saltpetre in cellars, stables, dovecotes, and other places where it was formed naturally. No one was permitted to pull down a building of any sort without first giving due notice to the salpêtriers. The “Salpêtrière” Asylum in Paris recalls one of the national factories of nitre. During the French Revolution citizens were “invited” to lixiviate the soil and ceilings of their cellars, stables, etc., and to supply the Republic with saltpetre for gunpowder. The Government paid 24 sous, 1s., a pound for the nitre thus procured, though, as this was no doubt paid in assignats, it was cheap enough. It was estimated that 16,000,000 lbs. a year were thus provided.

PETROLEUM.

Under the name of naphtha and other designations petroleum has been known and used from the earliest times. The Persians were the first, as far as is known, to employ it for lighting, and also for cooking. They likewise made use of it as a liniment for rheumatism. So in this country, a kind of petroleum was sold as a liniment under the name of British oil; and in America, long before the great oil industry had been thought of, petroleum was popular as a liniment for rheumatism under the name of Seneca Oil.

Asphalt, or Bitumen of Judæa, was used by the Egyptians for embalming. Probably they reduced its solidity by naphtha. Naphtha was employed by Medea to render the robe which she presented to her rival Glauca inflammable, and this legend is given to account for the name of Oil of Medea, by which petroleum was anciently known. It was no doubt the principal ingredient in the Greek Fire of the middle ages.

Petroleum has been called by many other names. Oil of Peter or Petre was a common one, meaning, like petroleum, simply rock oil. Myrepsus, in the thirteenth century, refers to it as Allicola. The monks called it sometimes oil of St. Barbarus, and oil of St. Catherine.

Dioscorides said naphtha was useful as an application in dimness of sight. Two centuries ago it was occasionally given in doses of a few drops for worms, and was frequently applied in toothache. Petroleum Barbadense, Barbadoes tar, had some reputation in pectoral complaints in the seventeenth and eighteenth centuries, and was admitted into the P.L. as the menstruum for sulphur in the balsamum sulphuris Barbadense.

PHOSPHORUS.

Phosphorus, or its Latin equivalent, Lucifer, was the name given by the ancient astronomers to the planet Venus when it appeared as a morning star. When it shone as an evening star they called it Hesperus. Do we invent such seductive names now, or do they only seem attractive to us because they are ancient or foreign?

The phosphorescent properties of certain earths had been occasionally noticed by naturalists, but no observation of the kind has been traced in ancient writings. The earliest allusion to a “fire-stone” known occurs in the work of a gossipy French historian named De Thou. In a history of his own times this writer relates that in 1550, when Henri II made his state entry into Boulogne on the occasion of its restoration to France by the English, a stranger in foreign costume presented the king with a fire-stone which, he said, had been brought from India. De Thou narrates that this wonderful stone glowed with inconceivable splendour, was so hot that it could not be touched without danger, and that if confined in a close space it would spring with force into the air.

Sometime early in the seventeenth century, a shoemaker of Bologna, one Vincent Cascariolo, who, in addition to his ordinary business dabbled in alchemy, discovered a stone in the neighbourhood of his city which was luminous in the dark. The stone, which is now known to have been a sulphate of barium, and which the shoemaker calcined, ground, and formed into little round discs about the size of a shilling, and sold for a fancy price, was called the sun-stone. The discs, exposed to a strong light for a few minutes and then withdrawn into a dark room, gave out the incandescent light which we know so well. The discovery excited keen interest among scientific men all over Europe.

About 1668 two alchemists named Bauduin and Frueben, who lived at Grossenhayn in Saxony, conceived the idea of extracting by chemical processes the spirit of the world (Spiritus Mundi). Their notion was to combine earth, air, fire, and water in their alembic, and to obtain the essences of all of these in one distillate. They dissolved lime in nitric acid, evaporated to dryness, exposed the residue to the air, and let it absorb humidity. They then distilled this substance and obtained the humidity in a pure form. History does not tell us what questions they put to their spirit of the world when they had thus caught it. It appears, however, that the stuff attained a great sale. It was supplied at 12 groschen the loth, equal to about 1s. 6d. per ounce, and lords and peasants came after it eagerly. Rain-water would have been just as good, Kunckel, who tells the story, remarks. But one day Bauduin broke one of the vessels in which was contained some of the calcined nitrate of lime, and he observed that this, like the Bologna stone, was luminous in the dark after exposure to sunlight. Bauduin appreciated the importance of his discovery, and, taking some of his earth to Dresden, talked about it there. Kunckel, who was then the Elector’s pharmacist, and keenly interested in new discoveries, heard about this curious substance, and was very curious to find out all he could. He visited Bauduin and tried to draw from him the details of his process. But Bauduin was very shy of Kunckel, and the latter has left an amusing account of an evening he spent with his quarry. Kunckel tried to talk chemistry, but Bauduin would only take interest in music. At last, however, Kunckel induced Bauduin to go out of the room to fetch a concave mirror to see if with that the precious phosphorus (for Bauduin had already appropriated this name to the stuff) would absorb the light. While Bauduin was gone Kunckel managed to nip a morsel with his finger-nail. With this, aided by the fragments of information he had been able to steal from Bauduin’s conversation, he commenced to experiment by treating chalk with nitric acid, and ultimately succeeded in producing the coveted luminous earth. He sent a little lump of it to Bauduin as an acknowledgment of the pleasant musical evening the latter had given him.

It was now 1669. Kunckel was visiting Hamburg, and there he showed to a scientific friend a piece of his “phosphorus.” To his surprise the friend was not at all astonished at it, but told Kunckel that an old doctor in Hamburg had produced something much more wonderful. Brandt was the name of the local alchemist. He had been in business, had failed, and was now practising medicine enough to keep him, but was devoting his heart and soul and all his spare time to the discovery of the philosopher’s stone. The two friends visited Brandt, who showed them the real “phosphor” which he had produced, to which, of course, the other substances compared as dip candles might to the electric light, but nothing would induce the old gentleman to disclose any details of his process. Kunckel wrote to a scientific friend happily named Krafft at Dresden about the new “phosphor.” Honour seems to have been cheap among scientific friends at that time, for Krafft posted off to Hamburg, without saying anything to Kunckel about his intention, caught Brandt in a different humour, or perhaps specially hard-up, and bought his secret for 200 thalers.

According to another story, the German chemist Homberg also succeeded in securing Brandt’s secret by taking to him as a present one of those weather prognosticators in which a figure of a man and another of a woman come out of doors or go in when it is going to be wet or fine, as the case may be; a toy which had just then been invented.

Stimulated perhaps by Brandt’s obstinacy and Krafft’s treachery, Kunckel set to work and in time succeeded in manufacturing phosphorus. It may be taken as certain that he had picked old Brandt’s brains a little, and his own skill and shrewdness enabled him to fill up the gaps in his knowledge. However he acquired the art, he soon became the first practical manufacturer of phosphorus.

Brandt discovered phosphorus because he had arrived at the conviction that the philosopher’s stone was to be got from urine. In the course of his experiments with that liquid, phosphorus came out unexpectedly from the process of distilling urine with sand and lime.

The new substance excited great curiosity in scientific circles all over Europe, but the German chemists who knew anything about it kept their information secret, and only misleading stories of its origin were published. Robert Boyle, however, who was travelling on the Continent when the interest in the discovery was keenest, got a hint of the method of manufacture, and on his return to England proceeded to experiment. His operator and assistant in these investigations was Ambrose Godfrey Hanckwitz, who became the founder of a London pharmaceutical business which still exists. Ultimately Boyle and Hanckwitz were completely successful, and for many years the “English phosphorus” supplied by Hanckwitz from his laboratory in Southampton Street, Strand, monopolised the European market. According to a pamphlet published by him, entitled “Historia Phosphori et Fama,” the continental phosphorus was an “unctuous, dawbing oyliness,” while his was the “right glacial” kind.

In 1680 Boyle deposited with the Royal Society, of which he was then president, a sealed packet containing an account of his experiments and of his process for the production of the “Icy Noctiluca,” as he called his phosphorus.

It is related in the Memoirs of the Academy of Sciences of Paris for 1737 that in that year a stranger appeared in Paris and offered for a stipulated reward to communicate the process of making phosphorus to the French Government. A committee of the Academy, with Hellot as its president, was appointed to witness the stranger’s manipulation. According to the report of this committee, the experiment was completely successful.

It only remains to add, to complete the history, that in 1769, Gahn, a Swedish mine owner, discovered phosphorus in bones, and that working from this observation Scheele in 1775 devised the process for the manufacture of phosphorus which is still followed.

Such a remarkable substance as phosphorus, extracted as it had been from the human body, was evidently marked out for medical uses. Experiments were soon commenced with it. Kunckel’s “luminous pills” were the first in the field, so far as is known. His report was published in the “Chemische Anmerkungen” in 1721. He gave it in three-grain doses, and reported that it had a calmative effect! Subsequently it was tried in various diseases by continental practitioners. Mentz commended it in colic, Langensalz in asthenic fevers, Bonneken in tetanus, Wetkard in apoplexy, and Trampel in gout.

In 1769 Alphonse Leroy, of Paris, reported a curious experience. He was sent for to a patient apparently on the point of death from phthisis. Seeing that the case was hopeless, he prepared and administered a placebo of sugared water. Calling the next day, Leroy found his patient somewhat revived, and on examining the sugar which he had used for his solution, he found that some phosphorus had been kept in it for a long time. The patient was much too far gone to recover, but she survived for fifteen days, and Leroy attributed this amelioration to the phosphorised water which he had accidentally given her.

Gahn discovered phosphorus in the bones in 1768, and in 1779 another German chemist named Hensing ascertained its presence in a fatty matter which he extracted from the brain. Medical theories were naturally based on these observations. Couerbe, a French chemist quoted by Dr. Churchill, wrote thus in 1830:

“The want of phosphorus in the brain would reduce man to the sad condition of the brute; an excess of this element irritates the nervous system, excites the individual, and throws him into that terrible state of disturbance called madness, or mental alienation; a moderate proportion gives rise to the sublimest ideas, and produces that admirable harmony which spiritualists call the soul.”

British practitioners took but very little notice of phosphorus as a remedy in the first century of its career, although it remained for a large part of that period an English product.

It is rather curious, too, that neither in this country nor on the Continent did it get into the hands of the empirics, as mercury, antimony, and other dangerous drugs did. It may be supposed that it was not so much the danger that checked them as the pharmaceutical difficulties in the way of preparing suitable medicines. The earliest preparations of phosphorus, such as Kunckel’s pills, were a combination of it in a free state with conserve of roses. This method was gradually abandoned on account of the difficulty of subdividing the phosphorus so perfectly that the dose could be measured accurately. But as Dr. Ashburton Thompson remarks,[3] “although it is not so specifically mentioned, the uncertainty of action which imperfectly divided phosphorus exhibits” had something to do with the rejection of the old formulas. That is putting it very gently. The three-grain doses must have killed more people than they cured. The author just quoted says that in the early days “the dose employed seldom fell below 3 grains, while it occasionally rose as high as 12 grains.” Even Leroy, he adds, instituted his experiments by taking a bolus of 3 grains, and he did not seriously suffer from it. The recommended dose has been regularly declining. In 1855 Dr. Hughes Bennett gave it at one-fortieth to one-eighth of a grain. The Pharmacopœia now prescribes one-hundredth to one-twentieth of a grain.

THE HYPOPHOSPHITES.

The hypophosphites in the form of syrup were introduced by Dr. J. F. Churchill, of Paris, as specifics in consumptive diseases about 1857. His preference of these salts over the phosphates was based on the theory that the deficiency in the system in a phthisical condition was not of phosphates, which had been completely oxidised, but of a phosphide in an oxidisable condition, and this requirement was fulfilled by the hypophosphites. The latter he compared to wood or coal, the phosphates to ashes, so far as active energy was concerned. Dr. Churchill’s interest in a special manufacture of the hypophosphite syrups prejudiced the medical profession against his theories, and it is not certain that he got a fair hearing in consequence. The general verdict was that his results were not obtained by other experimenters, but for a good many years past syrups of the hypophosphites have been among the most popular of our general tonics.

Phosphorus is soluble in alcohol, ether, chloroform, bisulphide of carbon, and to a very small extent in water.

* * * * *

Phosphor paste as a vermin killer was ordered by the Prussian Government to be substituted for arsenical compounds in 1843, and it is probable that to some degree the alteration has been successful, though in France it was found that phosphorus in this form became a popular agent for suicide and criminal poisoning.

SAL PRUNELLA