Chapter 19

B.By the application of certain re-agents, or tests, to its solutions.

a.Fused Nitrate of Silver, or Lunar Caustic.For this test we are indebted toMr. Hume, who first suggested its application in thePhilosophical Magazine for May 1809, (vol. xxxiii). His method of using it is as follows: into a clean Florence flask introduce two or three grains of the suspected substance, in the state of powder, to which add about eight ounces of rain or distilled water, and heat the solution until it begins to boil; then while it boils frequently shake the flask, and add to the hot solution a grain or two of sub-carbonate of potass, agitating the whole to make the mixture uniform. Pour into a wine glass about two table spoonsful of the solution, and touch the surface of the fluid with a stick of lunar caustic. If arsenic be present, a beautiful yellow precipitate will instantly proceed from the point of contact, and settle towards the bottom of the glass as a flocculent and copious precipitate. By this test the 60th part of a grain may be satisfactorily recognised in two ounces of water. The presence of some alkali is essential to the success of the experiment, since arsenious acid is incapable, by the operation of simple affinity, to decompose thenitrate of silver.[251]The validity of this test has been questioned on several distinct grounds, and which the author has endeavoured to answer in another work[252]; such, however, is the importance of the question in its judicial consequences, that we shall re-consider it on the present occasion.

Objection 1.The alkaline Phosphates are found to produce precipitates with silver, analogous in colour and appearance to the arsenite of silver.This constituted one of the principal points in the evidence for the defence, on the trial ofDonnallfor the murder ofMrs. Downing(see Appendix, p. 299), and it must be admitted as a valid objection, if the experiment be performed in the manner just stated; but there are other reagents which will immediately distinguish these bodies, as we shall presently have occasion to state, under the history of theAmmoniuret of silver, as a test for arsenic. The author has also shewn that there is a mode of so modifying the application of the present test, that no error or doubt can arise in the use of it, from the presence of any phosphoric salt. This method consists in conducting the trial on writing paper, instead of in glasses; thus—drop the suspected fluid on a piece of white paper, making with it a broad line; along this line a stick oflunar causticis to be slowly drawn several times successively,when a streak is produced of a colour resembling that known by the name ofIndian Yellow; and this is equally produced by the presence of arsenic, and that of an alkaline phosphate, but the one from the former is rough, curdy, and flocculent, as if effected by a crayon, that from the latter is homogeneous and uniform, resembling a water-colour laid smoothly on with a brush; but a more important and distinctive peculiarity soon succeeds, for, in less than two minutes the phosphoric yellow fades into asad green, and becomes gradually darker, and ultimately quite black; while, on the other hand, the arsenical yellow remains permanent, or nearly so, for some time, when it becomes brown. In performing this experiment the sun-shine should be avoided, or the transitions of colour will take place too rapidly. It would be also prudent for the inexperienced operator to perform a similar experiment on a fluid known to contain arsenic, and on another with a phosphoric salt, as a standard of comparison.

In this way thenitrate of silver, without the intervention of any other test, is capable of removing every ambiguity, and of furnishing a distinguishing mark between the chemical action of arsenic and that of the phosphates.Mr. Hume[253]states that he has repeated this modification of his experiment with entire satisfaction; and that, in a late unfortunate case of poisoning, he derived considerable information by its application. One of the great advantages of this test is the very small quantity that is required for examination, and which will therefore never prevent our pursuing the subject through the other channels of investigation.

Objection 2.The muriates produce precipitateswith silver, so copious and flocculent, as to overcome every indication which the presence of arsenic would otherwise afford.

From the general use of common salt, the chemist must be prepared to meet with amuriatein almost every examination after arsenic, besides which this latter substance is occasionally adulterated with themuriate of barytaand bysulphate of lime.Dr. Marcetproposes to obviate the difficulties which the presence of amuriatemust occasion, by adding to the fluid to be examined dilutenitricacid, and then cautiously applying thenitrate of silveruntil all precipitation ceases; in this way the muriatic acid will be entirely removed, while the arsenic, if present, will be retained in solution, and may be afterwards rendered evident by the affusion of ammonia, which will instantly produce the yellow precipitate in its characteristic form. It must, however, be confessed, that this mode appears complicated, and, moreover, requires some chemical address for its accomplishment; it should be also known that the yellow precipitate thus produced is not always permanent, for it is soluble in an excess ofammonia. Under these circumstances, it is surely preferable to precipitate at once from the fluid under examination, all the substances which nitrate of silver can affect, and then to expose the mixed and ambiguous precipitate, so obtained, to a low heat, in a glass tube, when the arsenious acid will be separated by sublimation. In this way the presence ofmuriatesand evenphosphates, may, in certain cases, be serviceable, especially if the quantity of arsenic be very minute; for, by increasing the bulk of the precipitate, we shall decrease the difficulty of its examination.

Objection 3.Chromate of potass produces with nitrate of silver a yellow precipitate, which, when placedside by side with one produced by arsenious acid, cannot be distinguished by colour or appearance from it.This fact has lately been announced by Dr. Porter, of the University of South Carolina (Silliman’s Journal,iii.355); but as the presence ofChromate of Potasscan never be suspected in any research after arsenic, in cases of forensic interest, it is unnecessary to enter into any details respecting it.

We have stated above, that in consequence of the inability of arsenious acid to decomposenitrate of silverby simple elective attraction, the presence ofsomealkali becomes indispensable in the examination; and for this purposeDr. Marcetsuggested the superior advantages which would attend the application ofammonia, in all those cases where the arsenic had not been previously combined with a fixed alkali; since the former does not, when added singly, decompose nitrate of silver; a circumstance which, in using the fixed alkalies, is very liable to occasion fallacy. This ledMr. Humeto improve his original plan, by forming at once a compound,[254]which he calls theAmmoniaco-nitrate of silver, but which may with more propriety be designated, as anammoniuretof that metal.

b.TheAmmoniuret of Silver. This is an improvement of considerable value; for, while it obviates the necessity of ascertaining the exact proportion[255]ofalkali required in each experiment, it possesses the desirable property of not in the least disturbing the solution ofphosphate of soda.

c.Sulphate of Copper.This test of arsenic is the one discovered byScheele; when added to thearsenite of potassa beautiful green precipitate (constituting a pigment known by the name ofScheele’s green) is produced; “so decidedly,” saysDr. Bostock, “does this phenomenon indicate the presence of arsenic, that I thought it desirable to ascertain, as exactly as possible, what were the best proportions in which the ingredients should be employed, and in what way they should be mixed, so as to exhibit the effect in the most obvious manner. After a number of trials, in which the substances were employed in various quantities, and under different circumstances, I am disposed to recommend that the proportions of thearsenic, thepotass, and thesulphate of copper, should be to each other as the numbersone,three, andfive, respectively; for instance, if one grain of arsenic and three grains of potass, be dissolved in two drachms of water; and, in another equal quantity of water, five grains of sulphate be dissolved, we have two solutions, which are transparent, and nearly colourless; but upon mixing them together, the whole is converted into the most beautiful grass-green, from which a copious precipitate of the same hue slowly subsides, leaving the supernatant fluid nearly without colour. If the same materials are employed, in the same manner, but without the arsenic, a delicatesky-blueis formed, which is so decidedly different from the former colour as not to admit of the possibility of error.” In this experiment then, as well as in that with the nitrate of silver, it is necessary that the arsenious acid should be combined with an alkalinebase; and for the same reason, in order to bring the double elective attractions into play;Mr. Humehas accordingly availed himself of the property of ammonia, to form anammoniuret of copper, which is to be made according to the formula already given for the preparation of the silver test.

d.Ammoniuret of Copper.In using this test care must be taken that it be not too highly concentrated, for in that state it will not produce precipitation.

Notwithstanding the confidence with whichDr. Bostockhas supported the pretensions of theSulphate of Copper, as an infallible test for arsenic, its validity has been lately called in question, and it has been stated that adecoction of onionshas the property of imparting to the copper precipitate, produced by a fixed alkali, a green colour and appearance completely analogous to that which is occasioned by the presence of arsenic. This opinion was boldly advanced, and supported, on the trial ofDonnall, before alluded to, and of which we have given a very ample report in theAppendix. Since this event an opportunity occurred which enabled the author to examine this alleged fact, by a fair and appropriate series of experiments,[256]the result of which hassatisfactorily proved that the opinion was grounded on an optical fallacy, arising from theblueprecipitate assuming agreencolour, in consequence of having been viewed through a yellow medium.[257]Thephosphoric salts may also, under similar circumstances, be mistaken for arsenic; for the intense blue colour of thephosphate of copperwill, when viewed through a yellow medium, necessarily appear green. Such instances of optical fallacy are by no means uncommon in the history of chemical reagents; thuscorrosive sublimatehas been said to possess alkaline characters, in consequence of appearing to turn the syrup of violets green, whereas this apparent change is to be solely attributed to the optical combination of the yellow hue of the sublimate with the blue colour of the violet.

Whenever therefore such a source of fallacy can be suspected, the operator would do well to repeat his experiment on white paper, in the manner we have already pointed out, when treating of the silver test; and let it be remembered that the results, when obtained in glasses, should always be examined by day light, and viewed by reflected, and not by transmitted light.Dr. Bostockobserves, that a weak solution of the sulphate of copper, without any addition, when held between the eye and the window, frequently presents a greenish tinge. It should be also known that the usual reaction of theammoniuret of copper, upon a diluted solution of arsenic, is prevented by the presence oftannin; strong tea may therefore render the test inefficient.

e.Sulphuretted hydrogen.This is a very delicate test for arsenic, producing with its solution a beautiful golden coloured liquor, which, after a short time, lets fall a precipitate, and which will take place sooner if a small quantity of acetic acid be added. By thisre-agent so small a quantity as 1/100000 may be detected in solution. The test, however, is not, saysDr. Bostock, sufficiently discriminative to be depended upon alone; sincetartarized antimonyand some other bodies, will produce phenomena that may be mistaken for the effects of arsenic. It has, however, the merit of not being affected bytannin, and may therefore be conveniently employed for precipitating arsenious acid, when dissolved in tea.

f.Lime waterproduces with the solution of arsenic a beautiful white precipitate ofarsenite of lime, which easily dissolves in an excess of arsenious acid.

The precipitates occasioned by the foregoing reagents, should be carefully collected, and treated withblack flux, in a glass tube, for the purpose of obtaining the metallic sublimate, as above described.

We cannot quit this part of our subject without directing the reader’s attention to the chemical evidence given byDr. Addington, on the trial ofMary Blandy(see Appendix, p.241) to prove that arsenic was contained in a powder with which she was supposed to have poisoned her father. To those in the least acquainted with the habitudes of arsenious acid, it must be evident, that no one of the appearances described byDr. Addingtonindicates the presence of arsenic;[258]and his evidence is only to be reconciled upon the supposition that, instead of the arsenic itself, he, in this case, detected the foreign substances with which it had been adulterated; thus it has been before stated thatwhite arsenic, as sold by the druggists, is often adulterated withsulphate of lime; and the decomposition of this substance by thesub-carbonateof ammonia(“Spirit of sal-ammoniac”) or by thesub-carbonate of potass(“Lixivium of tartar”) would occasion the precipitation of a white substance, as stated in the evidence; it is however difficult to account for the “considerable precipitation of a lightish coloured substance” by muriatic acid (spirit of salt) by the presence of any impurity likely to be contained in the arsenic, or in the water employed for its solution. If any lime were present, it would probably give “white glittering crystals” of sulphate of lime, by the addition of sulphuric acid (spirits of vitriol). The only plausible evidence of the presence of arsenic in the suspected powder is “the alliaceous smell and white flowers” whichDr. Addingtondescribes as occurring when it was thrown on red hot iron; it must however be confessed, that from the fallacy of the other experiments, it is even impossible to place any confidence in those last mentioned.

Arsenic does not blacken a knife by which it is cut, as stated on the trial ofEliza Fenning; nor does it, when mixed with dough, prevent its rising.[259]

We have now concluded our history of the different tests which have been proposed for the detection of arsenic. Much has been said and written upon the relative degree of confidence to which they are respectively entitled, and it has been asserted on several occasions, that nothing short of the reproduction of the metal ought to be received by the tribunals of justice, as an unequivocal proof of the presence of arsenious acid. (SeeDr. Neale’s Evidence on the trial of Donnall.Appendix, p.297.) In takingan impartial review of all the evidence which the investigation of this subject can furnish, it must appear to the most fastidious, that theSilverandCoppertests, above described, are capable, under proper management and precaution, of furnishing striking and infallible indications; and that in most cases they will be equally conclusive, and in some even more satisfactory in their results, than the metallic reproduction upon which so much stress has been laid; and for this obvious reason, that unless the quantity of metal be considerable, its metallic splendour and appearance is often very ambiguous and questionable. The author is personally acquainted with a case, where the medical person, by no means deficient in chemical address, actually ascribed the presence of arsenic to that which was no other than a film of finely divided charcoal: in this state of doubt the last resource was to ascertain whether it yielded, or not, upon being volatilized, an alliaceous odour. Surely an unprejudiced judge would prefer the evidence ofsight, as furnished by the tests, to that ofsmell, as afforded in the experiment to which we allude; especially after the various fallacies, which we have shewn in the course of the present enquiry, to have occurred with regard to this latter sense. But the question at issue may be easily disposed of to the satisfaction of all parties; for let it be remembered, that the application of chemical reagents on solutions suspected to contain arsenic, so far from throwing any obstacle in the way of themetallic reproductionof that substance, are the very steps which should be adopted as preparatory to the “experimentum crucis.” It is only necessary to collect the precipitates, and to decompose them in the manner already described; and this confirmation of ourresults should never be neglected, for it is the bounden duty of the forensic chemist, who is called upon to decide so important a question as the presence of a corrosive poison, to prosecute by the fullest enquiry every point which admits of the least doubt; he should also remember that in a criminal case, where the life of a human being depends upon his testimony, he has not only to satisfy his own conscience, but that he is bound, as far as he is able, to convince the public mind of the accuracy and truth of his researches.

2.The Arsenious Acid is mixed with various alimentary and other substances.

The detection of the presence of arsenic, amidst a complicated mass of alimentary matter, has long been a problem of interest and difficulty. In the directions which have been already offered for the discovery of arsenic in solution, we have in some measure anticipated several of the resources, of which we are now to avail ourselves. It has been seen how greatly coloured fluids are capable of obscuring, and changing, and even altogether preventing, the arsenical indications.M. Orfila, with an assiduity and accuracy which so eminently characterise all his toxicological labours, has accordingly investigated the peculiar appearances assumed by the arsenical precipitates in different media, such as bile, tea, coffee, wine, broth, jelly, &c. Since the publication of the great work[260]in which these phenomena are recorded, its author has proposed a new method[261]of removing itsdifficulties andembarrassments, occasioned by the colouring matter of the above media; which consists in a previous application ofChlorine, so as to change the colour to a shade, that will not offer any optical impediment to the characteristic indications of the tests in question. We are ready to admit that such a mode of proceeding may, on certain occasions, assist the accomplished chemist in his analysis; but in the hands of a person less accustomed to chemical manipulation, we hesitate not to declare that it is subject to fatal fallacies; whereas, by collecting the precipitate, and submitting it to the process of sublimation we shall at once obtain the arsenious acid in a pure form, and be enabled to test it, in distilled water without the chance of error. Why then should we attempt to pursue our game through the windings of a labyrinth, when a direct road lies before us by which we may drive it into the open plain?

We accordingly recommend the juridical chemist, who suspects the presence of arsenious acid in broth, coffee, or any coloured liquid, to add a solution ofammoniuret of silver, and thus to precipitate indiscriminately all the bodies which it may be capable of so affecting. The precipitate may then be collected, and submitted to heat in a glass tube, as before directed.

But theArsenious acidmay perchance be so mixed with various foreign matter as to render its separation by filtration difficult; in such a case, after having boiled it in distilled water, in order to procure all the soluble matter from it, the residual mass may be evaporated to dryness, care being taken that the heat applied for such a purpose never exceeds 250°Fah.or we shall lose the arsenic, should any be present, by volatilization. The residue thus obtained may then besubmitted to a higher temperature in a subliming vessel, in order to procure the arsenious acid in its pure state. This process applies particularly to the examination of the matter vomited, or the feculent evacuations passed, by the patient. Should the arsenious acid have, in the first instance, been dissolved in oil,Dr. Ureproposes to boil the solution in distilled water, and to separate the oil afterwards by the capillary action of wick threads. If the arsenious acid be mixed with resinous bodies,Oil of Turpentinemay be employed as their solvent, which will leave the arsenic untouched.Dr. Blackdirected the application of alcohol for this purpose, but this is obviously improper, since arsenious acid is soluble in that fluid.

If the physician be called upon to investigate the contents of the alimentary canal after death, and the arsenious acid cannot be discovered amongst the suspected matter, the stomach itself must be cut into small pieces, and in compliance with the directions ofOrfila, boiled in ten or twelve times their weight of distilled water, which should be renewed as fast as a portion of it flies off in vapour; this liquor should be cooled and decanted, in order to put a few drops of it into the solutions of the different re-agents which we have before described. If the precipitates should indicate the presence of arsenic, we may proceed according to the directions we have already laid down; if, on the other hand, the fluid offers no indication of poison, the mass exhausted by water should be treated, according to the process suggested byRose, by boiling it for some time in a solution of potass, by which means the stomach will be partly decomposed and dissolved, and the arsenious acid, with which it might have been combined, saturated by the alkali. In this state the liquor is to be filtered, again boiled,and nitric acid added, little by little, until it passes from a dark to a clear yellow colour. The object of the acid in this stage of the process being to decompose and destroy the animal matter. The excess of acid should be saturated with potass, when anArsenite of Potasswill be formed, if there really existed any arsenious acid in the stomach. ThisM. Orfilarecommends us to precipitate by theHydro-sulphuret of Ammonia, and a few drops of nitric acid; (Rosepreferslime waterfor the same purpose); a yellowsulphuret of Arsenicwill be the result, from which the whole of the metal may be obtained, by drying it upon a filter, mixing it with an equal bulk of potass, and melting it in a small glass tube.

This complicated mode of proceeding will rarely be found necessary; but it should not be neglected, where the presence of arsenic cannot be otherwise detected in the alimentary canal of those who are suspected to have died from its ingestion, especially in the examination of a body where, from the length of time it may have been under ground, there is reason to suppose that the acid exists in a state of intimate combination with the animal matter. And we may take this opportunity to observe, that advanced putrefaction, however disagreeable it may render such researches, will not, in the case of arsenic, defeat their success; let the forensic physician, then, remember, that the length of time which may have elapsed since the death of the body, ought never to be urged as a plea for not having proceeded in its dissection. The task may be personally disagreeable, but it will be less painful than the reflections which must attend a breach of duty; upon such an occasion we would address the anatomist in the quaint but expressivewords ofTeichmeyer[262], “Præstat enim manus quam conscientiam cruentare et contaminare.”

It has been stated, that the Metal Arsenic is susceptible of two degrees of oxidizement, the result of its first degree being Arseniousacid, and that of its second Arsenicacid. This latter compound, of which we are now to treat, may be obtained by the repeated distillation of white arsenic with nitric acid. In a solid state it is white, not crystallizable; of a sour, and at the same time, metallic taste; its specific gravity is 3·391; when exposed to the action of heat in a close vessel, it does not become volatile, but melts and vitrifies; thrown on burning coals, it swells, parts with its water, and becomes opaque; if the process of deoxidation be continued, it will, at length, rise in vapours, like those of arsenious acid, and which, like them, will yield an alliaceous odour, or not, according to the circumstances already explained. TheArsenic aciddissolves very readily in water, and is even indeed deliquescent. With alkalies, earths, and oxides, it constitutes a class of salts, called “Arseniates,” all of which, as well as the pure acid, are extremely active poisons; fortunately, however, they are not much employed[263]in this country, and are not likely to become the instruments of crime. These salts, like those of the arsenious acid, are obedient to the different re-agentswhich were enumerated under the consideration of this latter substance, but with different results; thus thesilvertest, instead of producing the yellow indication, occasions an equally characteristic precipitate of a red, or brick colour. The ammoniuret, and acetate of copper, furnish a bluish-white precipitate. The arsenic acid, in a solid form, or the arseniate, mixed with black flux, will, like white arsenic, furnish a metallic sublimate, when heated in a glass tube.

There are two Sulphurets of Arsenic: the yellow variety known in commerce under the name ofOrpiment, and the red sulphuret, termedRealgar. The bodies, as they occurnative, do not appear to be endowed with the virulent powers which distinguish the other compounds of arsenic.M. Renault[264]gave as much as two drachms of the native orpiment to dogs of different sizes, from which they experienced no inconvenience.Hoffman[265]also offers his testimony of the inertness of this substance. The same observations apply to theRealgar. It is not a little singular that while these native sulphurets of arsenic should be so harmless, those which are produced by artificial fusions, are extremely virulent in very small doses.M. Renaultsupposed that this remarkable difference of effect was owing to the arsenic being oxidized in the latter compound, and in its metallic state in the former. This explanation, however, is not considered as satisfactory byM. Orfila, who states that it does not embrace all the varietiesof the case, for that thesulphuret, which is artificially obtained by pouring the arsenious acid into a solution of sulphuretted hydrogen, is as inert as the native compounds; besides which, chemical analysis has proved that there is no oxygen in any of thesesulphurets, and that they only differ from one another, by a greater or less proportion of their two ingredients. This apparent anomaly inducedM. Orfilato institute a series of experiments for its investigation, but the results which he has obtained are too unsatisfactory to enable him to decide the question.

The presence of anArsenical Sulphuretis to be sought for by calcination with caustic potass, in a small glass tube. The sulphuret is decomposed in a few seconds, yielding its sulphur to the potass, while its metallic element is volatilized with the usual phenomena.

Mercury, or Quicksilver[266], was known in the earliest ages. Its external characters are too familiar to require any particular description in this place. Its specific gravity is 13·568.[267]In its metallic state it exerts no action on the living system, except that which may depend upon its mechanical properties, although a different opinion has been entertained, (seePharmacologia, art. Hydrargyrum.)

Several of the combinations of this metal are, however, highly destructive in small doses, and are consequently objects of forensic interest.

Corrosive Sublimate.

Oxy-muriate of Mercury. Bi-chloride of Mercury.

This metallic salt is by far the most active of all the mercurial preparations. According to the latest views of Chemistry it is a compound of two proportionals of chlorine, and one proportional of metallic mercury, and is therefore abi-chloride of Mercury. It generally occurs in the form of a crystalline mass, made up of very small prismatic crystals, which undergo a slight alteration by exposure to air, becoming opaque and pulverulent. Its taste is extremely acrid, with a metallic astringency, occasioning a sensation of obstruction in the throat which continues for some time. Its specific gravity is 5·1398[268]. When pulverised and thrown upon burning coals, it is immediately volatilized, giving out a thick white smoke, of a very pungent smell, not at all resembling garlic, but which irritates the mucous membranes extremely, and is highly dangerous to those who breathe it. It is soluble in eleven parts of cold, and in three of boiling water; and this solubility may be farther increased by the addition of a few drops of rectified spirit, or of muriatic acid. When swallowed in small quantities it acts as a most virulent poison.[269]

The effects, as well as themodus operandi, of this salt, will vary with the quantity swallowed. We shall, therefore, first consider the acute symptoms which supervene a dose sufficiently powerful to destroy life in a few hours; and afterwards those whichmay arise from its long continued use in small quantities, and at different intervals.

1.Symptoms which follow a large dose.A most painful burning and sense of constriction is experienced in the fauces; dryness of the mouth and lips; excruciating pain in the stomach and bowels, increased by the slightest pressure, and generally attended with considerable distention; excessive vomiting and purging of frothy mucus; the countenance is frequently red and swollen, and the eyes exhibit a sparkling appearance, accompanied by contraction of the pupils. The pulse is in general quick, small, and hard; suppression of urine takes place, and cold sweats; anxiety; universal pains; convulsions, and death. If the patient survives long enough, a violent ptyalism, and sloughing of the mouth and gums may take place.

2.Symptoms which are produced by the repetition of small doses.In this case the mercurial salt acts as an “Accumulative Poison.” (See page148). The most striking of the symptoms are those arising from its specific action upon the salivary glands, in consequence of which an increased flow of saliva takes place, the gums become tender and sore, the breath intolerably offensive, and if the use of the salt be not discontinued, the teeth loosen, and even fall out, and their loss is sometimes followed by that of the bones of the palate, or maxillæ; at the same time other evils, although perhaps less apparent, soon arise; the strength and muscular powers of the body begin to fail; emaciation proceeds rapidly; cardialgia, dyspepsia, diarrhæa, and a train of morbid symptoms succeed; violent pains are experienced in the muscles, tendons, or joints; tremors of the limbs, and even paralysis may result; and in some cases, pulmonaryconsumption terminates the existence of the unhappy sufferer. It has been asserted thatCorrosive Sublimate, when taken for a long time in small quantities, will sometimes occasion all the symptoms of debility above enumerated, together with hectic fever, without producing salivation. This is a truth which the author’s personal experience will enable him to confirm. The Countess of Soissons, mother of the celebrated Prince Eugene, was accused, at the latter end of the seventeenth century, of having destroyed her husband by these means. A question of considerable importance has arisen, with regard to the specific effects of mercury, which demands some notice in this place.Whether salivation, after having entirely subsided, can ever return without a fresh exhibition of Mercury?Two instances are related byDr. Meadof the return of salivation, after an interval of several months, when not a particle of mercury had been administered, in any form, during that period.[270]Dr. Male, in his work on Juridical Medicine,[271]relates an analogous case which occurred in his own practice: “In March, 1815,” says he, “I gave a small quantity of triturated mercury to a respectable woman in this town, who had been long ill; she became suddenly and unexpectedly salivated. She soon recovered, and enjoyed better health than she had done for a considerable time. In October, without (as she informed me) having taken any medicine whatever, the salivation returned with extreme violence, her mouth sloughed and mortified; and in a few weeks she died.”Dr. Hamilton, the Professor of Midwifery in Edinburgh, relates in his lectures the case of a married lady, who had beenunder the necessity of going through a course of mercury, under the care of the lateMr. Bennet, who, from motives of delicacy did not enquire very minutely into the particular circumstances; but, according to the rule of the day, gave his patient a sore mouth. Four months afterwards she miscarried, and salivation again came on. It was removed for a week, at the end of which it returned, and harrassed her for about twelve months.[272]The author, in hisPharmacologia,[273]has cited a case fromHufeland’s Journal, (vol. ix) wherein mercurial influence, after its complete subsidence, had been renewed by doses of opium. In the trial ofMiss Butterfield, at the Croydon assizes, for poisoningMr. Scawen, in the year 1775, the merit of the case entirely hinged upon this question. See vol. 1, p. 303.

When this salt is introduced into the stomach in a large dose, it immediately exerts a corrosive action on that organ, in consequence of which the heart and brain become sympathetically affected, and death results from the suspension of their functions. For this view of themodus operandiof this mercurial salt we are indebted toMr. Brodie,[274]whence it would appear that its physiological action is very different from that of arsenious acid; the former acting as a simpleescharotic, on the coats of the alimentary canal,the latter requiring to be absorbed, before it can display its energies. These observations, however, apply only to those cases in which the quantity of poison has been so considerable as to destroy life in a few hours; where the dose has been small, and the symptoms have arisen from its frequent repetition, the salt produces its effects by a different mode of operation. In this latter case it is absorbed, and carried into the current of the blood, so as to be distributed to every part of the living system; and it has been asserted that, after the long continued and improper use of mercury, it has been discovered in different parts of the body, and even in the brain, in the form of globules. In this way then deleterious effects may arise from the external application of corrosive sublimate, and numerous instances are recorded where such consequences have followed the injudicious use of lotions and plasters, into which it had entered as an ingredient.[275]In theMedical Repository, for December, 1821,Mr. Sutleffehas communicated the case of a girl of five years of age, who became salivated, and died, in consequence of an application made to the head fortinea capitis, consisting of pomatum rubbed up with a few grains ofcorrosive sublimate.

After the view which we have taken of the operation of this salt in large doses, it necessarily follows that copious dilution is the very first object which we have to accomplish, and then the ejection of the fluid by vomiting.Sydenhamrelates an interesting case of poisoning by this substance, which was successfully treated by copious draughts of water, and repeatedvomiting.[276]But it becomes a question of great practical importance to enquire, whether there may not exist some counterpoison or antidote which, by decomposing the salt, will at once disarm it of its virulence? This question has been investigated in a very masterly style byOrfila, who has clearly proved by experiment, that neither thealkaline saltsandearths, the sulphurets of potass and of lime, nor themartial alkaline tinctures, as proposed byNavier,[277]deserve the least confidence; for although the salt may by some of these bodies be decomposed, yet the resulting oxide will prove as virulent as the original compound; equally inefficient are the other substances which have been proposed as counter-poisons, such assulphuretted hydrogen,solutions of sugar,[278]the infusions of Peruvian bark,[279]andmetallic mercury.[280]

M. Orfilahaving observed the facility with whichalbumendecomposes corrosive sublimate, and gives rise to a triple compound of albumen, muriatic acid, and protoxide of mercury, induced him to ascertain by experiments whether thewhite of eggsmight notprove an antidote to that poison; the result of his inquiry has shewn that this is the case; and that by mixing such albuminous matter, inlarge quantities, with the diluents given to provoke vomiting, the happiest effects may be anticipated. Many examples are recorded of the success of this practice. In the Transactions of the King and Queen’s College of Physicians in Ireland, an interesting case of this kind is related byDr. Lendrick; it is, however, but justice to state, that there are instances also of the failure of this antidote. In the 41st volume of theLondon Medical and Physical Journal, p. 204, the reader will find the case of a girl who was poisoned by a drachm of sublimate, and who, notwithstanding the copious administration of albumen, died in ninety hours afterwards.

It has lately been discovered that vegetablegluten, as existing in wheat flour, is capable of producing upon corrosive sublimate the same chemical decomposition, as that which we have stated to arise from the action of albumen; whence the administration of wheat flour and water has been suggested as a ready antidote. On the trial ofMichael Whiting, for administering poison (corrosive sublimate) to his brothers-in-law,GeorgeandJoseph Langman, the housekeeper,Catharine Carter, stated in evidence, that the flour, (which was subsequently proved to contain corrosive sublimate) could scarcely be made into dumplings with milk[281]; and another witness,Mrs.Hopkins, a neighbour who took charge of the dumpling that had not been boiled, described it as “a comical sort of paste; like glazier’s putty more than paste, though not greasy.” In order to ascertain the correctness of this statement, we mixed powdered sublimate with wheat flour, and proceeded to make it into dough with milk; when the same difficulty as that stated by the above witnesses, embarrassed the process, and satisfied us of the truth of their testimony. The phenomenon would appear to depend upon the mutual chemical changes which arise in the gluten and mercurial salt.

The œsophagus and stomach will be found inflamed, and sometimes eroded, as in poisoning by arsenic.Salinhas asserted, that this salt never produces perforation of the intestinal tube; this, however, is not the fact; and we know not of any exclusive appearances, by which the organic lesions inflicted by this poison can be distinguished, unless indeed it be the black appearance of the stomach, as if it had been burnt, which occasionally presents itself.

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