CHAPTER XVII.

OF POISONING WITH TIN, SILVER, GOLD, BISMUTH, CHROME, ZINC, AND IRON. Several other metallic compounds produce effects analogous to those of the preparations of arsenic, copper, mercury, and antimony. But they may be passed over shortly; because they are little known as poisons, and it is therefore only necessary that their leading properties be mentioned. They are the compounds of tin, silver, gold, bismuth, chrome, zinc, and iron. _Of Poisoning with Tin._ The chlorides of _tin_ are used in the arts of colour-making and dyeing, and the oxide of tin forms part of the putty-powder used for staining glass and polishing silver plate. There are two chlorides, the protochloride and bichloride. They both form acicular crystals, which are very soluble. It is needless to notice their tests or chemical history; but in order that the following account of their effects on man and animals may be understood, it is necessary to mention, that they are decomposed by almost all vegetable infusions and animal fluids. Orfila found, that a solution of six grains of the protochloride injected into the jugular vein of a dog killed it in one minute,—that two grains caused death by tetanus in fifteen minutes,—and that so small a quantity as half a grain caused death in twelve hours, the only symptoms being somnolency and catalepsy or fixedness of position. To these dreadful effects when introduced into the blood, its effects when swallowed are not nearly proportionate. From eighteen to forty-four grains killed dogs in one, two, or three days, efforts to vomit and great depression being the only symptoms; and after death the stomach was found excessively inflamed, and sometimes ulcerated. Its effects when applied externally are still less violent. Two drachms applied to a wound merely caused violent inflammation and sloughing of the part, and death in twelve days, without any internal symptom during life or appearance after death.[1166] These phenomena, considered along with the violent symptoms excited when the poison is injected into the veins, show that, when swallowed or applied outwardly, it acts only as a local irritant. Tin is absorbed in the course of its action, and may be detected in the liver, spleen, and urine, by boiling them in water acidulated with hydrochloric acid, evaporating the decoction to dryness, charring the residue by means of nitric acid as directed for copper, treating the carbonaceous mass with a mixture of twenty parts of hydrochloric acid and one of nitric acid, evaporating the solution to dryness so as to expel any excess of acid, dissolving what is left in hydrochloric acid diluted with twice its volume of water, and then transmitting hydrosulphuric acid gas. If the precipitated sulphuret of tin has not a fine yellow colour, it must be heated with a little strong nitric acid; after which, if the residuum be again dissolved in diluted hydrochloric acid, a characteristic yellow bisulphuret will be thrown down by hydrosulphuric acid gas. This process may be applied to all organic mixtures containing tin.[1167] The oxide of tin, according to Schubarth, is quite inactive; for he gave an entire drachm to a dog without being able to observe any effect from it whatever.[1168] This is what would be expected from its extreme insolubility. Yet Orfila has stated in the early editions of his Toxicology, and repeats in that of 1843, but without noticing the contradictory observations of Schubarth, that one or two drachms of the oxide occasion in dogs all the phenomena of irritant poisoning, and prove invariably fatal.[1169] The metal has been proved by Bayen and Charlard to be inactive.[1170] It has been given expressly to dogs without any effect being observed; and it is given in large doses to man for worms, without detriment. No importance therefore can be attached to some alleged cases of poisoning with this metal.[1171] Cases of poisoning with the preparations of tin are rare. Orfila briefly notices a set of cases which occurred to M. Guersent. Several persons in a family took the protochloride, in consequence of the cook having mistaken a packet of it for salt and dressed their dinner with it. They had all colic, some of them diarrhœa; none vomited; and all recovered in a few days.[1172] A case is related in the Medical Times of death apparently caused by so small a quantity as half a tea-spoonful of a solution of protochloride. The effects were vomiting, acute pain in the stomach, anxiety, restlessness, thirst, and a frequent, hard, small pulse. These symptoms increased next day; and on the third day death took place, preceded by delirium.[1173] As this was a case of suicide, it is probable that some other poison, or a larger dose of the chloride of tin was taken. Little need be said of the morbid appearances. Besides the signs of violent irritation caused by the poisons of tin in common with other irritants, Orfila always found in dogs a peculiar tanned appearance of the villous coat of the stomach. In the case from the Medical Times the gullet was red, the stomach inflamed externally, and internally thickened, vascular, and pulpy. _Of Poisoning with Silver._ Of the preparations of _silver_, the only one which requires notice is the nitrate or lunar caustic. It exists in two forms,—crystallized in broad, transparent, colourless tables,—and fused into cylindrical, crystalline, grayish pencils. Both forms are essentially the same in chemical nature.—The most convenient tests are, 1, _Hydrochloric acid_, or any hydrochlorate, which even in a state of extreme dilution causes with it a dense white precipitate, passing, under exposure to light, into dark brown; and 2, _Ammonia_, followed by the solution of oxide of arsenic; if the nitrate of silver is not too much diluted it gives a dark brown precipitate with ammonia, soluble, however, in an excess of that alkali; and when the solution has thus been restored, arsenic throws down a lively yellow precipitate, passing rapidly to brown, if left exposed to the light. Most organic substances, but in particular all animal fluids, with the exception of gelatin, decompose nitrate of silver. It appears from the experiments of Orfila, that, like the chlorides of tin, the nitrate of silver is a deadly poison when introduced into the veins; but that, by reason of its facility of decomposition, it cannot enter the blood through ordinary channels in a quantity sufficient to develope any remote action. When two grains in solution were injected into the jugular vein of a dog it died in six minutes, difficult respiration being the chief symptom; the third part of a grain caused death in four hours and a half, violent tetanus having preceded death; and in both animals the blood in the heart was found very black and the lungs gorged, or vivid red. According to Mr. Blake, the salts of silver when directly introduced into the blood, do not act on the heart, but operate by causing obstruction of the capillary system. If they are injected into the aorta, the systemic capillaries are obstructed, the nervous system is consequently oppressed, respiration is arrested through the medium of this nervous oppression, and death takes place by asphyxia, the heart continuing to beat vigorously. If again they are injected into a great vein, immediate obstruction of the pulmonary capillaries takes place, so that the blood ceases to be transmitted to the left side of the heart.[1174] To the violent action exerted by nitrate of silver when directly admitted into the blood, its effects through the medium of the stomach bear no proportion or resemblance. Thus, when twelve grains of the salt were introduced into the stomach in the solid state, its effects were so slight as not to be distinguishable from those of the ligature on the gullet practised to prevent its discharge by vomiting. When introduced in a state of solution, however, and in a larger dose, in the dose of 36 grains, for example, it is more energetic. Death ensued in thirty-six hours, but without any particular symptoms; and in the dead body the villous coat of the stomach was found generally softened, and corroded near the pylorus by little grayish eschars like those formed by this poison on the skin.[1175] Hence it appears that nitrate of silver does not act remotely, but simply as a local irritant and corrosive. The corrosion it produces is incompatible with its absorption in large quantity. This inference is confirmed by the experiments of Schloepfer, on its effects when introduced into the trachea. He found that it caused inflammation of the windpipe, and pneumonia passing on to hepatization of the lungs, but no symptom referrible to a remote action.[1176] Its pure corrosive properties have long pointed it out to the surgeon as the most convenient of all escharotics. Nitrate of silver is absorbed, however, in the course of its action. It would seem to be absorbed when it is taken medicinally in frequent small doses. It is not easy to account otherwise for the singular blueness of the skin, sometimes observed after the protracted use of lunar caustic as a remedy for epilepsy and other diseases.[1177] The effects of the poison on the constitution in such cases are not very well known. It appears, however, that considerable doses may be taken for a great length of time without injury, and that the first and only unpleasant effects produced by its too free administration are such as indicate simply an injury of the stomach. The only exception to this general statement I have met with is a case by Wedemeyer, where, after the remedy had been taken for six months on account of epilepsy, that disease disappeared, and dropsy, with diseased liver at the same time commenced, and soon proved fatal. It is probable, however, that the nitrate of silver had no share in the ultimate event. In this instance the whole internal organs were more or less blue; and metallic silver, it is said, was found in the pancreas, and in the choroid plexus of the brain.[1178] Silver has been found in the urine of persons who were taking it medicinally. A young man who had used the nitrate for some time observed that his urine became muddy soon after being passed, and that the sediment became black if exposed to the light; and when the sediment was digested in ammonia, chloride of silver was detached by neutralizing the ammoniacal liquor.[1179] But it also appears that some nitrate of silver is absorbed when it is given in a single large dose. For in animals poisoned with it Orfila found that silver may be detected in the liver and spleen by charring these organs with nitric acid as in the instance of poisoning with copper, and then treating the residue with boiling diluted nitric acid, and adding hydrochloric acid to the solution. He also found silver in the urine by charring the extract with heat, acting on the charcoal with ammonia, and saturating the filtered ammoniacal solution,—chloride of silver being then detached.[1180] These results have been confirmed by the experiments of Drs. Panizza and Kramer of Milan,[1181] who found silver in the blood after the administration both of the nitrate and chloride. Boerhaave has noticed a case of poisoning with this substance, but in very brief terms. He says it caused gangrene. Schloepfer in his thesis notices a case by Dr. Albers of Bremen in which croup was brought on by a bit of lunar caustic dropping into the windpipe. M. Poumarede has related an instance of poisoning with an ounce of nitrate of silver in solution. A few hours afterwards the individual was found insensible, with the eyes turned up, the pupils dilated, the jaws locked, and the arms and face agitated with convulsions. A solution of common salt was immediately given as an antidote. In two hours there was some return of consciousness, and abatement of the convulsions, but still complete insensibility of the limbs, with redness of the features, and pain in the stomach. In eleven hours he could articulate. For thirty-six hours he continued subject to fits of protracted coma; but he eventually recovered. Sixteen hours after taking the poison he vomited a large quantity of chloride of silver.[1182] The treatment of poisoning with the nitrate of silver is obvious. The muriate of soda by decomposing it will act as an antidote; and any signs of irritation left will be subdued by opium. _Of Poisoning with Gold._ _Gold_ in various states of combination was at one time much used in medicine, and an attempt has been lately made to revive its employment. Its poisonous properties are powerful, and closely allied to those of the chlorides of tin and nitrate of silver. In the state of chloride it occasions death in three or four minutes when injected into the veins, even in very minute doses; and the lungs are found after death so turgid as to sink in water. But if swallowed, corrosion takes place; the salt is so rapidly decomposed, that none is taken up by the absorbents; and death ensues simply from the local injury.[1183] It has been of late used in medicine in France as an antisyphilitic; but even doses so small as a tenth of a grain have been known to produce an unpleasant degree of irritation in the stomach.[1184] In the state of fulminating gold, this metal has given rise to alarming poisoning in former times, when it was used medicinally. Plenck in his Toxicologia says it excites griping, diarrhœa, vomiting, convulsions, fainting, salivation; and sometimes has proved fatal.[1185] Hoffmann likewise repeatedly saw it prove fatal, and the most remarkable symptoms were vomiting, great anxiety and fainting. In one of his cases the dose was only six grains.[1186] These compounds are now so little met with that they need not be noticed in greater detail. _Of Poisoning with Bismuth._ _Bismuth_, in its saline combinations, is also an active poison. One of its compounds, the trisnitrate, white bismuth, or magistery of bismuth, is a good deal used in medicine and the arts; and pearl white, one of the paints used in the cosmetic art, is the tartrate of this metal. The former substance is an active poison. It is got by dissolving bismuth in nitric acid, and pouring hot water over the crystals; a supernitrate being left in solution, and the trisnitrate thrown down in the form of a white powder. Orfila found that the soluble part of fifteen grains of the nitrate, when injected into the jugular vein of a dog, caused immediate giddiness and staggering, and death in eight minutes. He also remarked that forty grains mixed with water and introduced into the stomach, caused all the customary signs of irritation, and death in twenty-four hours; and that a great part of the villous coat of the stomach was reduced to a pulpy mass, and likewise exhibited several ulcers.[1187] Similar effects were produced by the trisnitrate; but a larger dose was required. Two drachms and a half killed a dog in twenty-four hours; and redness and eroded spots were found in the stomach. In some more recent researches Orfila found that the poison is absorbed, and may be detected, like other metallic poisons, in the liver, spleen, and urine. The process for this purpose, applicable also to all organic mixtures, consists in boiling the solids in water acidulated with a twentieth of nitric acid, evaporating the solution to dryness, charring the residue with nitric acid, as directed for copper, boiling the charcoal in diluted nitric acid, and thus obtaining an acid solution of nitrate of bismuth, which may be known by the effects of water and of hydrosulphuric acid.[1188] Orfila remarks, that Camerarius of Tübingen once detected the adulteration of wine with the oxide of bismuth, and that the bakers in some parts of England used to render their bread white and heavy by mixing the trisnitrate with flour; but he has not stated his authority for this accusation. It may be discovered in any such mixture by calcining the suspected substance in a crucible, and then separating the metallic bismuth by means of nitric acid. But the adulteration of bread with bismuth is very questionable, as there are many cheaper methods for effecting the purpose, without adding any thing positively deleterious. The following is the only case with which I am acquainted of poisoning with the preparations of bismuth in the human subject. A man subject to water-brash took two drachms of the trisnitrate with a little cream of tartar by mistake for a mixture of chalk and magnesia. He was immediately attacked with burning in the throat, brown vomiting, watery purging, cramps, and coldness of the limbs, and intermitting pulse, and then with inflammation of the throat, difficult swallowing, dryness of the membrane of the nose, and a constant nauseous metallic taste. On the third day he had hiccup, laborious breathing, and swelling of the hands and face; and suppression of urine was then discovered to have existed from the first. On the fourth day swelling and tension of the belly were added to the pre-existing symptoms, on the fifth day salivation, on the sixth delirium, on the seventh, swelling of the tongue and enormous enlargement of the belly; and on the ninth he expired. The urine continued suppressed till the eighth day.—On inspection of the body it was found that from the back of the mouth to the rectum there were but few points of the alimentary canal free of disease. The tonsils, uvula, pharynx, and epiglottis, were gangrenous, the larynx spotted black, the gullet livid, the stomach very red, with numerous purple pimples, the whole intestinal canal red, and here and there gangrenous, especially at the rectum. The inner surface of the heart was bright red. The kidneys and brain were healthy.[1189] _Of Poisoning with Chrome._ The next metal whose properties deserve notice is _chrome_. As it is now extensively used in the art of dyeing it is necessary to mention its effects, more especially as they are singular. They have been ascertained experimentally with great care by Professor Gmelin of Tübingen. He found that in the dose of a grain the _chromate of potass_ had no effect when injected into the jugular vein of a dog,—that four grains produced constant vomiting, and death in six days without any other striking symptom,—and that ten grains caused instant death by paralysing the heart. Its effects, when introduced under the skin, are still more remarkable. It seems to cause general inflammation of the lining membrane of the air-passages. When a drachm was thrust in the state of powder under the skin of the neck of a dog, the first symptoms were weariness and a disinclination to eat. But on the second day the animal vomited, and a purulent matter was discharged from the eyes. On the third day it became palsied in the hind legs; on the fourth it could not breathe or swallow but with great difficulty; and on the sixth it died. The wound was not much inflamed; but the larynx, bronchi, and minute ramifications of the air tubes contained fragments of fibrinous effusion, the nostrils were full of similar matter, and the conjunctiva of the eyes was covered with mucus. In another dog, an eruption appeared on the back, and the hair fell off.[1190] The effects of the salts of chrome on man have not been well ascertained, but seem to be peculiar. Dr. Schindler of Greifenberg relates the following case of fatal poisoning with bichromate of potash. A colourman having swallowed a solution of it, vomiting was brought on by warm water, soap and oil, and kept up until the discharges ceased to be yellow. The man got apparently well and passed a quiet night; but next morning he felt excessively weary, had stitches in his back and kidneys, passed no urine, and was affected with purging. A restless night followed. On the subsequent morning, he lay motionless and like one fatigued to the extremest degree; in which state he died, fifty-four hours after swallowing the poison. The stomach was healthy, the intestines reddish, the kidneys gorged with blood and marbled internally with dark-red patches, and the bladder empty.[1191]—Mr. Wilson of Leeds has described the case of an elderly man who took the poison in the evening, and was found dead about twelve hours afterwards, without any sign of vomiting, purging, or convulsions; and no morbid appearance was found but redness of the villous coat of the stomach, and an inky-like fluid in it, containing a large quantity of bichromate of potash.[1192] To these facts may be added another not less singular, which my late colleague Dr. Duncan informed me has been observed by the workmen in Glasgow, who use the bichromate of potass in dyeing. When this salt was first introduced into the art of dyeing, the workmen who had their hands often immersed in its solution were attacked with troublesome sores on the parts touched by it; and the sores gradually extended deeper and deeper, without spreading, till they sometimes actually made their way through the arm or hand altogether.[1193] _Of Poisoning with Zinc._ The compounds of _zinc_, which have been long used in considerable doses in medicine, have sometimes occasioned serious and even fatal effects. Partly on this account, and partly because one of them, the sulphate of zinc, being the emetic most commonly used in the treatment of poisoning, is apt to complicate various medico-legal analyses, it will be proper to notice both its physiological properties and the mode of detecting it by chemical means. The only important compound of this metal is the sulphate or _white vitriol_. As usually sold in the shops, it forms small, prismatic crystals, transparent, colourless, of a very styptic metallic taste, and exceedingly soluble in water. That which is kept by the apothecary is tolerably pure; but there is a salt sometimes met with in commerce which contains an admixture of sulphate of iron, and with which the natural action of the tests for zinc is materially modified. The solution of the pure salt is precipitated white by the _caustic alkalis_, an oxide being thrown down, which is soluble in an excess of ammonia. The _alkaline carbonates_ also precipitate it white, the carbonate of ammonia being the most delicate of these reagents. The precipitate is soluble in an excess of carbonate of ammonia, and is not thrown down again by boiling. The precipitate produced both by the alkalis and by their carbonates becomes yellow, when heated nearly to redness; and on cooling it becomes again white. This is a characteristic property, by which the oxide of zinc may be known from most white powders. But oxide of antimony is similarly affected. The _ferro-cyanate of potass_ also causes a white precipitate. A stream of _sulphuretted-hydrogen_ likewise causes a white precipitate, the sulphuret of zinc, the colour of which distinguishes the present genus of poisons from all those previously mentioned, as well as from the poisons of lead. The precipitate is apt to be suspended till the excess of gas is expelled by ebullition. The action of this test will not distinguish sulphate of zinc from the salts of peroxide of iron, by which white sulphur is disengaged from the gas in consequence of the peroxide of iron being reduced to the state of protoxide. The same decomposition takes place wherever there is free chlorine, as in impure samples of muriatic or nitric acid. When the sulphate of zinc contains iron, the alkalis throw down a greenish-white precipitate, the alkaline carbonates a grayish or reddish-white, the ferro-cyanate of potass a light-blue, but sulphuretted-hydrogen the usual white precipitate. Tincture of galls, which merely renders the pure salt hazy, causes a deep violet coagulum if there is any ferruginous impurity. The sulphate of zinc is acted on by albumen and milk precisely in the same manner as the sulphate of copper. The salt is decomposed, and the metallic oxide forms an insoluble compound with the animal matter. When the sulphate of zinc has been mixed with vegetable and animal substances, the action of the tests mentioned above is modified. In such circumstances I have found the following process convenient. The mixture being strained through gauze, it is to be acidulated with acetic acid, and filtered through paper. The acetic acid dissolves any oxide of zinc that may have been thrown down in union with animal matter. The filtered fluid is then to be evaporated to a convenient extent, and treated when cool with sulphuretted-hydrogen gas,—upon which a grayish or white milkiness or precipitate will be formed. The excess of gas must now be expelled by boiling, and the precipitate washed by the process of subsidence and affusion, and collected on a filter. It is then to be dried and heated to redness in a tube. When it has cooled, it is to be acted on by strong nitric acid, which dissolves the zinc and leaves the sulphur. The nitrous solution should next be diluted, and neutralized with carbonate of ammonia; after which the liquid tests formerly mentioned will act characteristically. The effect of carbonate of ammonia, and that of heat on the carbonate of zinc which is thrown down, ought to be particularly relied on. I have tried this process with the matter vomited after the administration of sulphate of zinc, in a case of pretended poisoning, and found it to answer exceedingly well. Orfila has lately suggested the following method. Boil the suspected substance in water, evaporate the filtered decoction to dryness, char the residuum with nitric acid as directed for copper in similar circumstances, digest the charcoal in diluted muriatic acid, and subject the filtered solution to hydrosulphuric acid. If the sulphuret be not white, but yellowish from iron, heat it with strong nitric acid, dry the product, and heat it to redness; dissolve it in weak nitric acid; throw down the oxide of iron by an excess of ammonia, which retains the oxide of zinc; and then having filtered the fluid, separate the oxide of zinc by neutralizing the ammonia.[1194] Orfila has furnished the only accurate information hitherto possessed regarding the effects of sulphate of zinc on the animal system.[1195] He found that dogs might be made to swallow 7½ drachms without any permanent harm being sustained, provided they were allowed to vomit; for in a few seconds the whole poison was invariably discharged, and the animals, after appearing to suffer for four or five hours, gradually recovered their usual liveliness. But the result is different if the gullet be tied: violent efforts to vomit ensue, and death follows in three days, the intermediate phenomena being those of local irritation chiefly, and the appearances in the dead body those of incipient inflammation of the stomach, without corrosion.—When injected into the veins, the effect of sulphate of zinc is much more violent, in an inferior dose. Forty-eight grains occasioned almost instant death; and half the quantity proved fatal in three minutes. Orfila does not appear to have ascertained the cause of death in the last two experiments. But Mr. Blake found that when this salt is injected into the veins in the dose of three grains, it causes some depression of the heart; that thirty grains arrest the action of the heart in eight seconds, leaving that organ exhausted of irritability and full of florid blood in its left cavities; and that when injected into the arterial system in the dose of sixteen grains, it seemed not to cause any obstruction of the capillaries, but to act on the nervous system, producing extreme prostration, without insensibility or convulsions.[1196] These experiments, when taken together, show that sulphate of zinc, though a moderately active irritant, is more indebted for its activity to a remote operation on some vital organ. Sulphate of zinc is absorbed in the course of its action; for Orfila has lately found it by his process for complex mixtures in the spleen, liver, and urine of animals.[1197] The effects of the preparations of zinc on man in large doses have not been particularly studied. In the dose of a scruple or a drachm, the sulphate is the most immediate emetic known; and it is to be inferred, that if larger doses are rejected, as is the fact, with equal rapidity, they will in general cause no more harm than the medicinal dose. Nevertheless, some people have suffered severely from over-doses of sulphate of zinc, and a few have even perished. Instead of presenting here a general view of the symptoms, it will be preferable to relate the heads of such cases as have been published. The first to be mentioned is related by Foderé, who, in consequence of the violent symptoms produced, assigns to the present poison very active properties. “A patient of mine,” says he, “a custom-house officer, having got from a druggist six grains of sulphate of zinc to cure a gonorrhœa, was attacked with inflammation in the lower belly, attended by retraction of the navel and severe colic, which yielded only to repeated blood-letting, general as well as local, oleaginous emollients, opiates, and the warm bath.”[1198] This case is noticed here chiefly to prevent any one from being misled by it, as it has been quoted by other medico-legal authors. For assuredly some other cause must have co-operated before such symptoms could arise; since I have in many cases given the same dose thrice daily for several days, without ever observing more than slight sickness; and Dr. Babington once gave thirty-six grains thrice a day for some weeks with as little effect.[1199] Parmentier, the chemist, met with an instance, in which about two ounces of white vitriol in solution were swallowed by mistake. The countenance became immediately pale, the extremities cold, the eyes dull, and the pulse fluttering. The patient, a young lady, then complained of a burning pain in the stomach, and vomited violently. But potass being now administered in syrup, the pain ceased, the vomiting gradually abated, and the lady soon recovered completely.[1200] In the Journal de Médecine, another instance is related by M. Schueler, in which a very large dose did not produce material injury. The symptoms were pain in the stomach and bowels, with vomiting and diarrhœa. They were dispelled in a few hours by the administration of cream, butter, and chalk.[1201] The following is a fatal case recorded by Metzger, but it is not a pure example of poisoning with zinc, though accounted such by the relater; for a small quantity of sulphate of copper was mixed with the sulphate of zinc. Three persons in a family took this mixture, which had been given them by a grocer in mistake for pounded sugar. They were all seized with violent vomiting; and a boy twelve years of age died in less than twelve hours.[1202] Another and an unequivocal case has been lately recorded in Horn’s Archiv from Mertzdorff’s experience. No part of the history of the symptoms is mentioned, except that there had been vomiting. But Mertzdorff has described carefully the morbid appearances, which are interesting; and he detected the poison in the stomach by a satisfactory analysis.[1203] Two other cases, which are presumed to have arisen from the commercial sulphate of zinc, and which proved fatal, have been recently published by Dr. Sartorius of Aachen; but they do not appear to me to have been satisfactorily traced to this poison, and it is therefore unnecessary to quote them.[1204] Dr. Werres of Cologne has related the particulars of three cases of poisoning with some preparation of zinc in milk-porridge. One of the persons, a child four years old, was seized with vomiting in three minutes, and, after frequent violent returns of it, died in convulsions within eight hours. The others also suffered severely from vomiting, but recovered.[1205] It does not appear that workmen who are exposed to the fumes of zinc ever suffer materially. But there is a case in Rust’s Magazin, which shows that these fumes are not quite harmless. An apothecary’s assistant, while preparing philosopher’s wool, incautiously filled the whole laboratory with it. The same day he was seized with tightness in the chest, headache and giddiness; next morning with violent cough, vomiting, and stillness of the limbs; on the third day with a coppery taste in the mouth, some salivation, gripes, and such an increase of giddiness that he could not stand. He was then freely purged, after which a fever set in, ending in perspiration; and he got well in three weeks.[1206] From these cases, and the experimental researches of Orfila, it is clear that the preparations of zinc, though not very active poisons, are nevertheless far from being innocuous. We are not acquainted with their effects when long and habitually introduced into the body in small quantities. About the time when physicians began to study with care the dangerous consequences of employing lead and copper in the manufacture of culinary vessels, it was conceived by some that zinc might prove a safe substitute. It was farther imagined by some military economists in France, that zinc might be profitably used instead of tinned iron in the manufacture of canteens and other articles of camp equipage, because the worn and damaged vessels would sell as old metal at little short of their original price, while tinned iron as old metal bears no value at all. But from the experiments of Deyeux and Vauquelin it subsequently appeared, that in the course of many culinary operations zinc is more liable to be attacked than either copper or lead;—that water left for some time in zinc vessels oxidates them, and acquires a metallic taste;—that if water acidulated with vinegar or lemon-juice is boiled in zinc, a solution is formed, in which the metal may be detected by its tests;—and that sea-salt, sal-ammoniac, and even butter, have the power of dissolving it also.[1207] Some singular inquiries were afterwards prosecuted by Devaux and Dejaer among the Spanish prisoners at Liége, with the view of proving, that frequent small quantities of zinc dissolved in the manner mentioned, and habitually taken with the food, have no injurious tendency; that even in large doses it can hardly be accounted poisonous, as it merely gives rise to vomiting and slight diarrhœa; and that an adulteration to such an amount would always betray itself by its strong disagreeable taste.[1208] These are certainly valuable facts, though not quite satisfactory. But it is unnecessary to inquire minutely into their validity; for, independently of all other considerations, vessels constructed of zinc are too brittle for domestic purposes. With regard to the effects of frequent small doses of sulphate of zinc, the only positive information I can communicate is, that I have often given medicinally from three to six grains thrice a day for two or three weeks, without observing any particular effect except in some persons sickness when the largest doses were taken; and others have frequently made the same observation.[1209] On the other hand, Dr. Nasse of Berlin says a patient of his, who had taken twenty grains of oxide of zinc daily till 3247 grains were swallowed, was attacked with paleness, emaciation, weakness of intellect, obstinate constipation, coldness and œdema of the limbs, extreme dryness of the skin, and a thready scarcely perceptible pulse. But he quickly recovered under the use of laxatives and tonics.[1210] Sulphate of zinc is said to have proved fatal when applied externally. In Pyl’s memoirs there is a case of this nature, which was attributed to sulphate of zinc having been used as a lotion for a scabby eruption on the head. The subject was a child, six years old, and otherwise healthy. The wash, which was a vinous solution, had not been long applied before the child complained of acute burning pain of the head, which was followed by vomiting, purging, convulsions, and death in five hours. The cause of these symptoms, though the particulars of the case were ascertained judicially by an able medical jurist, Dr. Opitz of Minden, is nevertheless very doubtful, as daily use is made of the salt for similar purposes without any such effect. Appearances of congestive apoplexy were found within the skull; and the reporter ascribes death to the wash having produced repulsion of the cutaneous disease, and determination of blood to the head.[1211] The only opportunities which have occurred of observing the morbid appearances after poisoning with sulphate of zinc taken internally, are the cases by Metzger, Mertzdorff, and Werres. In the first, which was a mixed case, the only appearances of note were slight inflammation in the stomach, and excessive gorging of the lungs with fluid blood; from which Metzger oddly enough concludes that the child was suffocated by the vomiting. In the second case, Mertzdorff found the stomach and intestines, but particularly the latter, contracted,—their outer surface healthy—the inner membrane of the stomach grayish-green, with several spots of effused blood, and greenish, fluid contents,—the inner membrane of the small intestines similarly spotted,—the rest of the body quite natural. It has been already mentioned that Mertzdorff detected the poison in the body. He found it not only in the contents, but likewise in the coats of the stomach and intestines. In the third, Werres found a reddish-brown patch and some vascularity in the stomach. _Of Poisoning with Iron._ In previous editions of this work the preparations of iron were arranged among those substances which are not usually considered poisonous, but which may nevertheless prove injurious when taken in large quantity. But the soluble salts of iron, although not very active, seem sufficiently so to entitle them to a regular place among poisons; and one of them, the sulphate, has actually been used, as will presently appear, for the purpose of committing murder. There are many soluble salts of iron which in all probability may prove hurtful; but the only ones which have been brought under notice in medico-legal researches are the sulphate of the protoxide, and the mixed chlorides. The sulphate of the protoxide of iron, commonly called green vitriol or copperas, occurs in commerce in crystals or crystalline masses of various shades of bluish-green. It is easily known by its colour and its strong styptic inky taste. When in solution, the iron may be detected by ferro-cyanate of potash, sulphuretted-hydrogen, and tincture of galls. Ferro-cyanate of potash causes a blue precipitate, at first pale, but gradually passing to deep Prussian blue. Sulphuretted-hydrogen has no effect, but if an alkali, such as ammonia, be added to disengage the oxide of iron, a black precipitate of sulphuret of iron is immediately produced. Tincture of galls occasions a deep purplish-black precipitate, the tannate of iron, and it acts with greater delicacy in very diluted solutions, if the oxide of iron be disengaged by carbonate of soda. These tests prove the presence of iron in solution. A white precipitate under the action of nitrate of baryta will indicate that the oxide is dissolved by sulphuric acid. The most familiar form of chloride of iron is the tincture of the chloride, which sometimes contains only the sesquichloride, sometimes consists of a mixture of this with the protochloride. It is known by the three tests for oxide of iron described above, and by nitrate of silver occasioning a heavy white precipitate, insoluble in nitric acid. For detecting iron in organic mixtures, where the liquid reagents do not act satisfactorily, the simplest process is to digest the mixture, if there be any solid matter, in water acidulated with acetic acid, to evaporate the filtered liquid to dryness, to incinerate the extract in a porcelain crucible, to act on the product with diluted sulphuric acid, and then to treat the solution with the three liquid reagents. Professor Gmelin found that sulphate of iron merely caused vomiting in dogs who were made to swallow two drachms of it, that rabbits might take forty grains without any apparent injury, and that twenty grains in a state of solution might even be injected into the veins of a dog without producing any particular symptom.[1212] From these and some other facts of the like kind it was generally held, that sulphate of iron is not a poison. But Smith ascertained that a dose of two drachms will prove fatal to dogs in little more than twenty-tour hours, when it is introduced into the stomach, and in half that time if applied to a wound; and that it occasions some redness of the alimentary mucous membrane, and the effusion of a thick layer of tough mucus. It is remarkable, however, that, like Gmelin, he found no effect to flow from the transfusion of a solution of seven grains into the veins, except transient vomiting and expressions of pain.[1213] The effects which have been observed in the human subject are conformable with those witnessed in experiments on the lower animals, the symptoms being those of pure irritant poisoning. Few illustrative cases, however, have as yet been made public. In Rust’s Journal there is the case of a girl, who took as an emmenagogue, an ounce of green vitriol dissolved in beer, and suffered in consequence from colic pains, constant vomiting and purging for seven hours, but eventually recovered under the use of mucilaginous and oily drinks.[1214] A fatal case of poisoning with this substance occurs in the Parliamentary Returns of death from poison in England during the years 1837–38 [see p. 90].—Dr. Combe of Leith has communicated to me an instructive case of fatal poisoning with the tincture of the chloride of iron, which was taken to the extent of an ounce and a half by a gardener accidentally instead of whisky. Violent pain in the throat and stomach, tension and contraction of the epigastrium, and nausea immediately ensued; afterwards coldness of the skin and feebleness of the pulse were remarked; and then vomiting of an inky fluid, with subsequently profuse vomiting of mucus and blood, and also bloody stools under the use of laxatives. He remained for some days in a very precarious state, but then began to rally, and in three weeks resumed his occupation. But in two weeks more Dr. Combe found him emaciated, cadaverous in appearance, and affected with pains in the stomach, costiveness, and thirst; in which state he lingered for five days more, and then died. In the dead body there was found great thickening towards the pylorus, a cicatrized patch there three inches long and two inches broad, and another large patch of inflammatory redness surrounded by a white border. The preparation taken in this instance contained a third of its volume of hydrochloric acid and a tenth of its weight of oxide of iron; and consequently some of the acid was free. The following remarkable case, in which I was lately consulted on the part of the Crown, will show that sulphate of iron is a more important poison than has been commonly thought. Suspicions having arisen in December, 1840, respecting the death of a child in the county of Fife about four months before, an investigation was made by the law authorities; and the body was disinterred and inspected by Mr. Dewar and Dr. James Dewar of Dunfermline. It was ascertained that the child, a girl four years of age, and previously in good health, was attacked with violent vomiting and purging immediately after breakfasting on porridge, and died in the course of the afternoon of the same day. A boy two years older, having seen a blue solution put into the porridge, and observing that the porridge had a bad taste, took only three spoonfuls of it, but became for a time very sick. The girl, being fed by a woman in the house, was made to take all her share; and in the course of the day the same person was seen by two children of the family to give a blue solution to the sick girl for drink. The woman was proved to have purchased sulphate of copper, and admitted having bought about this time both that salt and sulphate of iron, for the alleged purpose of dyeing some clothes. Poisoning with sulphate of copper was therefore suspected. On examining the body, which had been buried four months, the Messrs. Dewar found the external parts considerably decayed,—the stomach soft, gelatinous, and of a uniform intense black colour through the whole thickness of its parietes,—the gullet and duodenum similarly affected, but not so deeply on their outer surface,—the spleen, kidneys, and lower parts of the liver similarly stained with a black pulp, which could be wiped off,—and the whole alimentary canal lined with a thick layer of jet-black mucus, from the pharynx down to the very anus. Inferring that the cause of this extraordinary blackness was decomposition of sulphate of copper by hydrosulphuric acid gas disengaged during the decay of the body, they proceeded to search for that metal in the form of sulphuret both in the contents and texture of the stomach, but without success: there was not a trace of copper to be found. Being then led from some circumstances in the analysis to suspect that the black matter might be sulphuret of iron, they proceeded to search for that substance, and ascertained that a large quantity existed both in the textures of the stomach and in the black mucus which lined it. They further ascertained that there was no iron in a state capable of being dissolved by water, but that a much larger quantity of sulphuric acid was associated with the black matter than could have proceeded from the sulphates naturally contained in the animal textures or in the mucous secretions. They had also an opportunity of examining several large buff-coloured stains on various articles of dress, worn by the child and by the woman at the time the poisoning was supposed to have happened; and they detected a large quantity of oxide of iron in all of them. The whole case was subsequently submitted to me for my opinion, together with a portion of the stomach, the entire intestines, and several stained articles of dress. The results of the analysis of the tissues of the stomach, the black intestinal mucus, and the stains on the cloth were the same in my hands.—It is not easy to see how any other conclusion could be drawn from the whole circumstances, than that a soluble preparation of iron had been administered a short time before death, and that it had been entirely decomposed and converted into sulphuret of iron by the evolution of hydrosulphate of ammonia during the decay of the body. In consequence of important defects in the evidence criminating a particular individual, and especially because all the essential facts depended on the testimony of children, who, after the lapse of some time, did not adhere to their original statement, it was judged improper to bring this case to a trial. A few years afterwards another case somewhat similar was submitted by the law authorities to the same gentlemen, to whom I am indebted for the particulars. A woman far advanced in pregnancy, and enjoying excellent health, was suddenly seized about midnight with vomiting and purging, and died in fourteen hours. Various circumstances having raised suspicions as to the cause of death, the body was disinterred a few days after burial, and carefully examined by Mr. Dewar and Dr. Dewar. The organs were in general healthy. There were some dark-red patches on the villous coat of the stomach, and a general blush pervaded the whole alimentary canal, which was empty of every thing but a reddish-brown mucus. The intestines were in several places irregularly contracted and hard. The stomach, small intestines, and rectum contained iron in large quantity, dissolved either by sulphuric or hydrochloric acid. Sulphate of iron was found in the house.—No trial took place in this instance either, because there was a want of evidence to attach guilt to any particular individual, although it was highly improbable that the woman had taken the poison herself.[1215] A short notice may here be added of the toxicological effects of the rarer metals, which have been examined chiefly by Professor Gmelin of Tübingen.[1216]—Oxide of _osmium_ is nearly as active as arsenic, for a grain and a half will kill a dog in a few hours by the stomach, and in one hour through a vein. Twelve grains of hydrochlorate of _platinum_ will kill a dog within a day through the stomach, with symptoms of pure irritation; and so will half that quantity through a vein.—The hydrochlorates of _iridium_ and _rhodium_ are rather less active.—The hydrochlorate of _palladium_ is equally powerful when introduced into the stomach, and much more so through a vein, for two-thirds of a grain will kill dogs in a minute. The salts of other metals appear less active.—_Molybdenum_, in the form of molybdate of ammonia, seems a feeble poison; thirty grains killed a rabbit in two hours, but produced in dogs merely some vomiting and purging; and ten grains injected into the jugular vein did not prove fatal.—_Manganese_, according to Gmelin, is likewise a feeble poison, but has peculiar effects. A drachm of the sulphate killed a rabbit in an hour. Thirty grains swallowed by a dog had no effect. Two drachms thrust into the cellular tissue had no effect. Twelve grains injected into a vein occasioned death in five days: and in the dead body, the stomach, duodenum, and liver were found much inflamed. Manganesic acid, according to Professor Hünefeld, appears also to act on the liver, but is a feeble poison. A rabbit received two drachms in three days in doses of ten or fifteen grains, without presenting any symptom except increased flow of urine. Being then killed, the liver was found soft, at one part bright red, elsewhere dark-brownish-red, and it yielded manganese by incineration.[1217] Some singular observations have been lately published by Dr. Couper of Glasgow, the purport of which is, that manganese belongs to the class of insidious, cumulative poisons, and that it has the property of slowly bringing on, in those who breathe or handle the oxide, a paraplegic affection which is incurable unless taken under treatment early. Five cases of the kind occurred subsequently to 1828, in the great chemical manufactory of Tennant and Company, among the workmen employed in grinding the black oxide of manganese.[1218] On the other hand, Dr. Thomson of Glasgow has recently stated that an ounce of sulphate of manganese is an effectual and safe laxative.[1219] _Uranium_ is an active poison when injected into a vein, for three grains of the muriate proves fatal instantly; but dogs may swallow fifteen, or from that to sixty grains without any other effect except slight vomiting [Gmelin]. _Cobalt_ is more active. Thirty grains of the oxide occasion death in a few hours through the stomach. Twenty-four grains of the muriate applied to the cellular tissue excite vomiting. Three grains of sulphate injected into a vein prove fatal in four days.—_Tungsten_, _cerium_, _cadmium_, _nickel_, and _titanium_ can scarcely be considered poisons. _Tungstate_ of ammonia in the dose of a drachm had no effect when swallowed by a dog; forty grains of tungstate of soda, which is more soluble, operated as an emetic; but this dose will prove fatal to rabbits in a few hours. A drachm of the muriate of _cerium_ had little or no effect on a dog, and half that dose had no effect on a rabbit. The oxide of _cadmium_ in the dose of twenty grains, made a dog vomit; and ten grains had no effect at all.[1220] Twenty grains of sulphate of _nickel_ made a dog vomit; forty grains applied to the cellular tissue had no effect at all on the general constitution; but ten grains injected into the jugular vein occasioned immediate death [Gmelin]. A drachm of _titanic_ acid had no effect on a dog.