Part 1

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Transcriber's note:

Text enclosed by underscores is in italics (_italics_).

Upright text within a block of italic text is enclosed by parenthesis marks [example: 〈Poisons)].

A carat character is used to denote superscription. A single character following the carat is superscripted (example: M^r).

A Mechanical Account of Poisons in Several Essays.

BY RICHARD MEAD, M.D.F.R.S. And Physician to St. _Thomas_’s Hospital.

_The Second Edition, Revised, with Additions._ _LONDON_:

Printed by _J. M._ for RALPH SMITH at the _Bible_, under the _Piazza’s_, of the _Royal Exchange, Cornhill_. 1708.

THE PREFACE

_〈To〉 give an exact and particular Account of the Nature and Manner of acting of 〈Poisons〉, is no easie Matter; but to Discourse more intelligibly of 〈Them〉 than Authors have hitherto done, not very difficult. One may without much Pains shew their Effects to be owing to something more than the bare Qualities of Heat or Cold; and Discover the Footsteps of 〈Mechanism〉 in those surprizing 〈Phænomena〉 which are commonly ascribed to some 〈Occult〉 or Unknown Principle. But to Unravel the Springs of the several Motions upon which such 〈Appearances〉 do depend, and Trace up all the Symptoms to their First Causes, requires some Art as well as Labour; and that both upon the account of the Exquisite Fineness, and marvellous Composition, of the Animal Machine in which they are Transacted, and of the Minuteness of those Bodies which have the force to induce in it such Sudden and Violent Alterations._

_I have attempted somewhat this way in the following 〈Essays〉; in which I do not promise Methodical, and Finish’d Treatises, but only some short Hints of Natural History, and Rude Strokes of Reasoning; which, if put together, and rightly Improved, may perhaps serve to furnish out a more tolerable SPECIMEN of the DOCTRINE of POISONS, than has yet been Published._

_The First Draught of this small Piece, I made some Years since, Entertaining my self at Leisure Hours, with Experiments on 〈Vipers〉, and other 〈Venomous Creatures〉; Examining now and then the Texture of 〈Arsenic〉, 〈Mercury Sublimate〉, and the like Malignant Substances; Turning over what Authors had said on the several Subjects, and making such Remarks as from Time to Time Occurr’d._

_There continued Enquiries made up at last, Three or Four short Discourses; which, when I began to Digest into Order, the Increase of Business contracted the Intervals of my spare Time; and the Diversion of such Studies quickly giving way to the Severity of more Necessary Labours, They were quite thrown by, Till Talking not long since with Dr. 〈Areskine〉, concerning the 〈Viper〉, I took Occasion to review my scattered Papers, and confirm my Reasonings by New Experiments. He very readily offered Me His 〈Anatomical Observations〉; These I have put at the End of the First 〈Essay〉; Which do not promise a 〈Complete Dissection〉 of the 〈Animal〉, but chiefly shew the Make of those Parts which are concern’d in the 〈Poison〉._

_My Design, in Thinking of These Matters, was, to Try how far I could carry 〈Mechanical Considerations〉 in Accounting for those Surprizing Changes, which 〈Poisons〉 make in an 〈Animal Body〉; Concluding (as I think, fairly) that if so abstruse 〈Phænomena〉 as These did come under the known Laws of Motion, It might very well be taken for granted, that the more obvious Appearances in the same Fabrick are owing to such Causes as are within the 〈Reach〉 of Geometrical Reasoning; And that therefore as the first Step towards the Removal of a Disease is to know Its Origin, so he is likely to be the best Physician, who having the same assistance of Observations and Histories with Others, does best understand the 〈Humane Oeconomy〉, the Texture of the Parts, Motions of the Fluids, and the Power which other Bodies have to make Alterations in any of These._

_Nor indeed ought any One to Doubt of This, who considers that the 〈Animal Compages〉 is not an irregular Mass, and disorderly Jumble of Atoms, but the Contrivance of Infinite Wisdom, and Master-piece of that Creating Power, who has been pleased to do all Things by Establish’d Laws and Rules, and that Harmony and Proportion should be the Beauty of all his Works._

_It were therefore heartily to be wish’d, that those Gentlemen who are so much afraid of Introducing 〈Mathematical Studies〉, that is, Demonstration and Truth, into the Practice of Physick, were so far at least Instructed in the necessary Disciplines, as to be able to pass a true Judgment, what Progress and Advances may be made this way; They would not then perhaps Decry an Attempt of so much Moment to the Wellfare of Mankind, as vain and impossible, because it is difficult, and requires Application and Pains._

_It is very evident, that all other Methods of Improving Medicine have been found Ineffectual, by the Stand it has been at these two or three Thousand Years; and that since of late 〈Mathematicians〉 have set Themselves to the Study of it, Men do already begin to Talk so Intelligibly and Comprehensibly, even about abstruse Matters, that it may be hop’d in a short time, if Those who are Design’d for this 〈Profession〉, are early, while their Minds and Bodies are Patient of Labour and Toil, Initiated in the Knowledge of 〈Numbers〉 and 〈Geometry〉, that 〈Mathematical〉 Learning will be the Distinguishing Mark of a Physician from a Quack; and that He who wants this necessary Qualification, will be as Ridiculous as one without 〈Greek〉 or 〈Latin〉._

_I have, as to what regards the 〈Animal Oeconomy〉, Referr’d as much as I could to the Works of 〈Bellini〉, which have brought great Light into the Dark Regions of Physick, and Taught Us to argue clearly and consistently, instead of Amusing our selves with Unintelligible Words or Precarious 〈Hypotheses〉. The 〈Dissertations〉 of Dr. 〈Pitcarne〉, who is the Honour of his Profession in 〈Scotland〉, are a Convincing Proof of the Advantage of such a Mechanical Way of Reasoning; nor could 〈Malice〉 it self deny This, were not 〈Ignorance〉 in Confederacy with it, which will secure any One from being Benefitted by the most useful Demonstrations._

_Notwithstanding This, I have been forced now and then to make Digressions from my Subject, to clear some Doctrines necessary to be known which have not been Explained by others. For indeed the 〈Data〉 from which We argue in these Matters are by many too few. Dr. 〈Cheyne〉, the Author of the 〈New Theory of Fevers〉, has enumerated several Particulars in which the 〈Theoretic〉 Part of Medicine still wants Improvement. If these 〈Deficiencies〉 were made good, We might with more Ease Proceed in our Enquiries into Human Nature, and should soon Convince the World, that the most useful of Arts, if duly Cultivated, is more than meer 〈Conjecture〉, or base 〈Empiricism〉._

_As to the Authors I have made use of, who have Treated of 〈Poisons〉, I have Quoted only those who Furnished me with Matter of Fact; For there are but few 〈Originals〉; and very large Volumes on this Subject do many times contain little more than a Collection of 〈Vulgar Errors〉._

_I had once Thought to have carried these 〈Searches〉 farther; in Particular, besides what is occasionally mention’d in the last 〈Essay〉 concerning 〈Infection〉 in acute Diseases, to have enquired into the Nature of 〈Contagious〉 and 〈Hereditary Distempers〉. But the Humour of Scribling would not hold out; And some perhaps will say, ’Tis well enough it didn’t; For I am not Ignorant how Few I am like to Please; If it be hard to Think and Write Justly, ’tis harder yet to Bring Others to one’s own 〈Taste〉; Nor shall I be at all Angry, if to Many I have afforded Matter of 〈Satyr〉 and 〈Invective〉; Less Wit suffices for These than for the Discovery of Useful Truths. They who have no Smattering of 〈Mathematical〉 Knowledge, are incompetent Judges of what Service I have done towards the Improvement of the 〈Theory〉, or 〈Practice〉 of 〈Medicine〉, and Those who are acquainted with these Matters, will, it may be, think it something to Talk Intelligibly on such difficult and abstruse Points. I neither want 〈Applause〉, nor fear 〈Censure〉; and therefore be the Fate of These Papers what it will, as they were first Penn’d for my own 〈Satisfaction〉, and Innocent 〈Entertainment〉; so I am resolved They shall never Ingage me in the Trouble of 〈Quarrels〉 or 〈Disputes〉._

THE CONTENTS.

ESSAY I.

_Of the Viper._

_An Appendix containing Anatomical Observations, and an Account of some other Venomous Animals._

ESSAY II.

_Of the 〈Tarantula〉 and Mad Dog._

ESSAY III.

_Of Poisonous Minerals and Plants._

ESSAY IV.

_Of Opium._

ESSAY V.

_Of Venomous Exhalations from the Earth, Poisonous Airs and Waters._

ESSAY. I.

OF THE VIPER.

The Viper has always been so Notorious for its Venom, that the most remote Antiquity made it an Emblem of what is Hurtful and Destructive. Nay, so terrible was the Nature of these Creatures, that they were very commonly thought to be sent as Executioners of Divine Vengeance upon Mankind for Enormous Crimes, which had escaped the Course of Common Justice. Thus _Herodotus_ (1) and _Ælian_ (2) do both take notice that Adders were sacred among the _Ægyptians_; that they affirmed of one sort of ’em particularly, that they were made to be Ministers of the Will of the Gods, by averting Evil from Good Men, and punishing the Bad. And _Pausanias_ (3) observes of the _Arabians_, that they forbore to offer any Violence to the Vipers which were found near to the Balsam-Tree, as reputing ’em Holy. The Footsteps of which Superstition do still remain among these People to this very Day, for _Veslingius_ (4) saw many of ’em take these Creatures into their Houses, feed ’em, and worship them as the _Genii_ of the Place. The same odd Fancy obtains in the _East-Indies_, for the King of _Calicut_ causes Cottages to be set up for Serpents to keep them from the Rain, and makes it Death to any that shall hurt one of ’em; thinking them to be Heavenly Spirits, because they can so suddenly Kill Men (5). A Remarkable Instance of such an Opinion as this we have in the History of St. _Paul_ (6), whom the People of _Malta_ when they saw the Viper leap upon his Hand, presently concluded to be a Murderer, and as readily made a God of him, when instead of having his Hand Inflamed, or falling down Dead, (one or other of which is usually the Effect of those Bites) he without any harm shook the Beast into the Fire. It being Obvious enough to imagine, that He must stand in a near Relation at least to the Gods themselves, who could thus Command the Messengers of their Vengeance, and Counterwork the Effects of such powerful Agents.

And this, after the many Conjectures upon the Matter, seems to be the true Reason why Antiquity not only Represented the First Masters of Physick, _Hermes_, _Æsculapius_, _Hippocrates_, &c. in their Statues and Medals, with a Viper added to their Figure, but also Worshipped them under this Form, for Diseases in those Days, especially the most Violent, Plagues, Fevers, _&c._ were in like manner, as these Creatures, reputed the Commission’d Messengers of Divine Anger and Displeasure (7). They therefore who by their Art could Cure and Stop the Course of these, as they were supposed to do this by the particular Leave and Assistance of Heaven, so had Honours paid to Them accordingly, and this Representation was in the Nature of an Hieroglyphick Character; for as the Learned _Spanhem_ observes, (8) the Viper was a Symbol or Emblem of Divine Power.

_Macrobius_ indeed gives us another account of this Custom, and that is from the Property which all Serpents have of casting their _Exuviæ_, or Upper-Skin, every Year, which makes ’em fit Emblems or Representations of Health; the Recovery of which from Sickness and Diseases may justly be looked upon as the beginning of a fresh Period of Life, and (as the throwing off the _Senectus_ of these Creatures seems to be) the Renewing of Age (9).

Whether one or the other of these Reasons be allow’d of, or both thought good, certain it is that such fond and superstitious Fancies concerning the Viper, together with the mistaken Opinion that few of its Parts were exempt from Poison, did not suffer the Ancients to make any Curious Enquiries into its Nature by Anatomy and Experiments, and this is the Cause of the many Errors they have delivered down to us in these Points, which by gradual Advances have since been rectified, and the inward Make, Properties, and Generation of this Animal, largely treated of; more especially M. _Redi_ (10), _Charas_ (11), and Dr. _Tyson_ in his Dissection of the _Rattle-Snake_ (12), which is a larger Species of a Viper, have taken Pains on this Subject, to whose Discoveries, what is yet wanting, we shall add at the End of this Essay.

The Symptoms which follow upon the Bite of a Viper, when it fastens either one or both its greater Teeth in any Part of the Body, are an acute Pain in the Place Wounded, with a Swelling at first Red, but afterwards Livid, which by degrees spreads farther to the Neighbouring Parts with great Faintness, and a Quick, tho’ Low, and sometimes Interrupted Pulse, great Sickness at the Stomach, with Bilious, Convulsive Vomitings, Cold Sweats, and sometimes Pains about the Navel; and if the Cure be not speedy, Death it self, unless the Strength of Nature prove sufficient to overcome these Disorders; and tho’ it does, the Swelling still continues inflamed for some time; nay, in some Cases more considerably upon the abating of the other Symptoms, than at the beginning; and often from the small Wound runs a sanious Liquor, and little Pustules are raised about it; the colour of the whole Skin is changed Yellow, as if the Patient had the _Jaundice_.

These Mischiefs, altho’ different Climates, Season of the Year more or less Hot, the greater or lesser Rage of the Viper, the Beast it self of a larger or smaller Size, and consequently able to communicate more or less Venom, and the like Circumstances, may variously heighten or abate ’em, yet do usually discover themselves much after the same manner in all; unless the Bite happen not to be accompanied with the Effusion of that _Liquor_, which is the main Instrument and Cause of this violent and shocking Disturbance.

But before I proceed to enquire into the Nature and Manner of Acting of this _Juice_, it may be worth the while to take Notice, that this is not made on purpose to be deadly and destructive to _Mankind_; but that the true Design of it is (tho’ Authors have not regarded it) to perform an Office and Service of so great Moment, to the Preservation of the Individual, that without it this Creature could not subsist.

For Vipers live chiefly upon Lizzards, Frogs, Toads, Mice, Moles, and the like Animals, which they do not chew, but swallow down whole, and they lie in the Stomach; or if that be not big enough to receive them, partly in that, and partly in the Œsophagus, which is membranous and capable of great Distension, till by the Salival Juices of those Parts, together with the Help of the Fibres of the Stomach, and the Contraction of the Muscles of the Abdomen, they are gradually dissolved into a Fluid Substance, fit for the Nourishment of their Bodies, which is the Work of many Days; this is _one_ Reason why these Creatures can live so long without taking any fresh Food, which I have known them to do Three or Four Months; as _another_ is, that their Blood is a grosser and more viscid Fluid than that of most other Animals; so that there is but a very little expence of it by Transpiration, and consequently less need of Recruit; this not only _Microscopes_ discover, but Reason teaches; because there is but very little Muscular Force in the Stomach to comminute the Food, and make a Chyle of fine Parts, and therefore the Blood must accordingly be of a Tough and Clammy Consistence. Besides, the Heart of a Viper has properly but one Ventricle, and the Circulation of the Blood is performed after the same Manner as it is in a Frog and Tortoise, in which not above one Third of it passes thro’ the Lungs; upon which Account its Comminution in them by the Air is proportionably lesser than in other Animals. Now such a manner of Feeding as _this_ does necessarily require, that the Prey should upon the first Catching be immediately kill’d, otherwise it were by no means fit to be let into the Stomach; for we are not to think that the Force of this Part would be alone sufficient to destroy it, the Subtilty of a living Creature (besides the Consideration of the Weakness of the Fibres) being in a great Measure able to elude _that_, as indeed we do every Day find live Animals in the Ventricles of others; and therefore to do _this_ is the proper Use both of the Teeth and their Poison; for which being designed and adapted, it is no wonder if the Viper, this same Way by which it destroys its Prey, proves sometimes mischievous to any other Creatures besides, when it happens to be enraged, or by any Provocation stirr’d up to bite.

The Description of the Poisonous _Fangs_, their Make, Articulation and Motion, as also of the Glands that separate the Yellowish Liquor, and the Bags that contain it; I shall give, together with some Anatomical Observations, at the End of this Discourse.

This Venomous Juice it self is of so inconsiderable a quantity, that it is no more than one good _Drop_ that does the Execution; and for this reason Authors have contented themselves with Trials of the Bite upon several Animals, never Essaying to examine the Texture and Make of the Liquor it self; for which purpose I have oftentimes by holding a Viper advantageously, and inraging it till it struck out its Teeth, made it to bite upon somewhat solid, so as to void its Poison; which carefully putting upon a Glass Plate, I have with a Microscope, as nicely as I could, viewed its Parts and Composition.

Upon the first Sight I could discover nothing but a Parcel of small Salts nimbly floating in the Liquor, but in a very short time the Appearance was changed, and these saline Particles were now shot out as it were into _Crystals_ of an incredible Tenuity and Sharpness, with something like Knots here and there, from which they seemed to proceed, so that the whole Texture did in a manner represent a _Spider’s Webb_, tho’ infinitely Finer, and more Minute; and yet withal so rigid were these pellucid _Spicula_, or _Darts_, that they remained unaltered upon my Glass for several Months (13).

I have made several Trials with this _Juice_ in order to find out under what Tribe of Salts these Crystals are to be ranged; and not without some difficulty, by reason of the Minute Quantity of the Liquor, and the Hazard of Experiments of this Nature, have plainly seen that it does, as an _Acid_, turn the blue Tincture of _Heliotropium_ to a Red Colour.

I did not succeed so well in mixing it with Syrup of Violets, and yet it did really seem to induce in this a _Reddish Hue_; but I am very certain it did not at all change it to a _Greenish_ Colour, as it would have done if any ways _Alcalious_.

This may suffice in their own way of arguing, to convince those Gentlemen, who without the Assistance of any Experiments, meerly to serve an _Hypothesis_ which they have too fondly taken up, have with great Assurance told the World, that the Viperine Venom is an _Alcali_, and consequently to be cured by _Acid_ Remedies. But it is by far more easie to Spin out a false Notion into precarious Reasonings, than to make faithful Experiments, and fairly improve ’em by just and necessary Consequences.

To proceed, this Discovery agrees very well with a Relation communicated by an Ingenious Person to Dr. _Tyson_, which does so much illustrate this Matter, that I shall transcribe it in his own Words, out of the before cited _Philosophical Transactions_; he says then, That being in the _Indies_, there came to him an _Indian_ with several Sorts of _Serpents_, offering to shew him some Experiments about the Force of their Poison; having therefore first pulled out a large One, the _Indian_ told him this would do no Harm; and making a Ligature on his Arm as in letting Blood, he exposed it naked to the Serpent, being first irritated to make him bite it; the Blood that came out of the Wound made by his Teeth, he gathered with his Finger, and laid it on his Thigh, till he had got near a Spoonful, after this he takes out another called _Cobra de Capelo_, which was lesser, and inlarges much upon the Greatness of his Poison; to shew an Instance of it, grasping it out about the Neck, he expresses some of the Liquor in the Bags of the Gums, about the Quantity of half a Grain, and this he puts to the coagulated Bleed on his Thigh, which immediately put it into a great _Fermentation_, and working like _Barme_, changed it into a _Yellowish_ Liquor.

This I say does well enough accord with what we have been advancing concerning the Nature of this _Juice_, for Mr. _Boyle_ has long since proved by Experiments, that there is nothing of Acid in human Blood; and Dr. _Pitcarn_ (14) has demonstrated, that the _Acid Substances_ of Vegetables taken into the Stomach, are by the Action of this Part, the Lungs and Heart, when they come into the Blood-Vessels, turn’d to _Alcalious_; so that the Arterial Fluid must necessarily be considered as an _Alcali_; and therefore according to the known Principles of Chymistry, its mixture with such a Liquor as we have discovered the Viperine _Sanies_ to be, will always exhibit some such appearance as this now related.

But not to engage any farther in these sort of Controversies, we may perhaps from the foregoing Observations receive some Light in order to understand the Nature and Reason of all those Symptoms which attend the Bite of this Creature. For the pungent Salts of this Venom, when with Force thrown into the Wound, will not only as so many _Stimuli_, irritate and fret the sensile Membranes, whereupon there necessarily follows a greater Afflux than ordinary of the Animal Juices that way, (as is manifest from the _Bellinian_ Doctrine, _De Stimulis_) so that the wounded Part must be Swelled, Inflamed, Livid, _&c._ but also these _Spicula_ being mixt with the Blood, will so disjoin and disunite the Parts of it, that its Mixture must be quite alter’d; and from the various _Cohæsion_ of its _Globules_ will arise such different Degrees of _Fluidity_ and _Impulse_ towards the Parts, _&c._ from what this Liquor had before, that its very Nature will be changed, or in the common way of speaking, it will be truly and really _Fermented_.

To understand aright how all this is done, it is necessary to hint somewhat concerning the Nature of _Fluids_ in General, and those Alterations in them which we call _Fermentations_; for I shall retain this known Word, tho’ in the proper Sense in which ’tis commonly used, there can be no _Fermenting_ of the Liquors in the Animal Body.