The protochloride or calomel, and probably also the protoxide, are the most manageable of the preparations of mercury for inducing ptyalism. Calomel is also an irritant; that is, it causes irritation and inflammation in the alimentary canal when swallowed. This part of its properties as a poison will require a word or two of explanation.
Calomel is universally employed as a laxative, but to secure this effect being produced it is commonly combined with other purgatives. When given alone a few grains will in some constitutions induce a violent hypercatharsis; and larger, but still moderate, doses have with most people such a tendency to cause severe griping and diarrhœa as to have led to the practice of combining it with opium when the object is to salivate. These considerations clearly establish that calomel, in a moderate dose of five or ten grains, is an irritant.
It farther appears that in larger doses it is said to have occasionally produced very violent effects, nay, even death itself, by its irritant operation. Hoffmann has mentioned two instances where fifteen grains of calomel proved fatal to boys between the ages of twelve and fifteen. One of them had vomiting, tremors of the hands and feet, restlessness and anxiety, and died on the sixth day. The other, he merely mentions, died after suffering from extreme anxiety and black vomiting.[997] Another fatal case has been related by Ledelius in the German Ephemerides, which was caused by a dose of half an ounce taken accidentally. Vomiting soon ensued, and a sense of acridity in the throat; then profuse diarrhœa to the extent of twenty evacuations in the day; next excessive prostration of strength and torpor of the external senses; and death followed in little more than twenty-four hours.[998] Wibmer quotes Vigetius, an author of the beginning of last century, for a similar case, likewise fatal, which was occasioned by half an ounce,—also Hellweg, a writer of the previous century, for the case of a physician, who took an ordinary medicinal dose by way of experiment, and died in five hours under all the symptoms of violent irritant poisoning.[999]
These observations being kept in view, what explanation will the toxicologist give of the effects which in modern times have been ascribed to large doses of calomel? It was stated not many years ago by several East India surgeons, apparently with the universal assent of their brethren in later times, that this drug in the dose of a scruple administered even several times a day, is not only not an irritant, but even on the contrary a sedative;[1000] and that in some diseases, for example yellow fever, it has been given in the dose of five, ten, or twenty grains, four or six times a day, till several hundred grains were accumulated in the body, yet without causing hypercatharsis, nay, with the effect of checking the irritation which gives rise to black vomit in yellow fever, and to the vomiting and diarrhœa observed in the cholera of the East. It is quite impossible for a European physician to doubt these statements; for all practitioners in hot climates concur in them, and now that analogous practices have been transferred to Britain, repeated opportunities have occurred for establishing the fidelity of the original reporters. Some American physicians, advancing beyond the Hindostan treatment, have since given calomel in bilious fever in the dose of forty grains, one drachm, two drachms, and even three drachms, repeatedly in the course of twenty-four hours for several days together,—and with similar phenomena. In one instance 840 grains were given in the course of eight days in these enormous doses. The largest dose was three drachms; and it was followed by only one copious evacuation, and that not till after the use of an injection.[1001] This practice appears not to have been altogether unknown in former times. Ledelius, the author formerly quoted, states, that he had been accustomed to give doses of a scruple, and that Zwölffer even gave a drachm in one dose.[1002]
It must be also added, that while the facts quoted above from Hoffmann, Ledelius, and others assign to single large doses a powerful and dangerous irritant action, very different results have been occasionally observed in recent times where even so large a quantity as one or two ounces had been taken. Thus, in the case of a lady mentioned by Wibmer, who took by mistake the enormous quantity of fourteen drachms, although acute pain in the belly ensued, together with vomiting and purging, these symptoms were speedily subdued by oleaginous demulcents; and after a smart salivation, she recovered entirely in six weeks.[1003] Another case has been related by Mr. H. P. Robarts, where an ounce was swallowed by a young lady by mistake for magnesia, with no other effect than nausea at first, rather severe griping and slight tenderness of the belly afterwards, and subsequently languor, headache and indigestion; yet the powder was retained two hours.[1004]
It is impossible in the present place to enter into the physiological action of calomel as a remedy; but every one must be satisfied that, with all which has been already written, much still remains to be done before the facts now mentioned can be explained satisfactorily. Can the violent effects described by Hoffmann, Ledelius and Hellweg have arisen from the calomel having been imperfectly prepared and adulterated with a little corrosive sublimate? Or may they be explained by reference to the fact, that the presence of hydrochlorates in solution, particularly hydrochlorate of ammonia, tends to convert calomel into corrosive sublimate.[1005] Mr. Alfred Taylor has made some experiments, to show that the latter explanation will not suffice.[1006]
Meanwhile, taking the facts as they stand, it is plain that great caution must be used in ascribing violent irritant properties generally, or even symptoms of irritant poisoning in a particular case, to large doses of calomel.
With the view of illustrating the importance of the preceding observations, it may be useful to mention here the heads of a case already briefly alluded to for another purpose, the trial of William Paterson for murder (319).[1007] His wife during the month previous to her death had two attacks of diarrhœa, with an interval of a fortnight between them. On the second occasion it became profuse and exhausting, but without any material pain or considerable vomiting; looseness of the teeth and salivation ensued, and she died in nine days. On examination of the body, the anus was found excoriated, the whole intestines checkered with dark patches, and the stomach red, ulcerated, and spotted with black, warty excrescences; but the late Dr. Cleghorn of Glasgow could not detect any poison by chemical analysis. It was proved that the prisoner, besides procuring, a few months before his wife’s death, a variety of poisons, such as hydrochloric acid, cantharides, and arsenic, had also on different occasions during her last illness purchased in a suspicious manner four doses of calomel varying from 30 to 60 grains each. Among the various ways in which he was charged with having poisoned the deceased, that which was best borne out by the general as well as medical facts consisted in his taking advantage of an existing inflammation of the mucous membrane of the bowels,—whether arising from a natural cause or from poison it was in this view of the case immaterial to inquire,—and keeping up and aggravating the inflammation by purposely administering at intervals large doses of calomel. On the trial Dr. Cleghorn and other witnesses gave their opinion that the doses purchased by the prisoner, if administered, would cause the symptoms and morbid appearances observed in the case. On the other hand, the late Dr. Gordon deposed to the effect, that all the symptoms of the case might arise under the operation of natural disease, and that such doses of calomel were by no means necessarily injurious; the late Mr. John Bell deposed, that it had even been given in much larger doses without injury; and the profession are now well aware, though not at the time of this trial, that in the very malady alleged by the prisoner to have carried off the deceased, namely dysentery, the administration of calomel in repeated large doses is accounted by many a proper method of cure. The doses purchased by the prisoner were considerably larger, it is true. But there was not any evidence of his having administered his purchases in single doses as he got them; and even though there had been evidence to that effect, it would not remove altogether the difficulty of deciding the question, as to the irritating action of calomel, on which the issue of the trial in one view of the case chiefly depended.
It is probable that all the compounds formed by corrosive sublimate with animal and vegetable substances are feebly poisonous, or at least very much inferior in activity to corrosive sublimate itself. This has been shown by Orfila to be the case with the compound formed by albumen. Sixty grains of this compound, being equivalent to nearly five grains of corrosive sublimate, produced no bad effect whatever on a dog or a rabbit.[1008] The same has been satisfactorily proved by Taddei as to the compound formed by gluten. Twelve grains of corrosive sublimate decomposed by his emulsion of gluten had no effect whatever on a dog.[1009] It is important to remark, however, that if there be an excess of the decomposing principle, so that the precipitate is party redissolved, the irritant action of the corrosive sublimate is not so much reduced, though it is still certainly diminished. Orfila has settled this point in regard to albumen.[1010] The power of producing mercurial erethysm is possessed by all mercurial compounds whatever, and among the rest by the compounds now under consideration.[1011]
The present section may now be concluded with a few remarks on the strength of the evidence derived from the symptoms which are produced by the compounds of mercury.
If the medical jurist should meet with a case of sudden death like that of the animals experimented on by Sir B. Brodie, the symptoms alone could not constitute any evidence of poisoning with corrosive sublimate. All he could say would be that this variety of poisoning was possible, but that various natural diseases might have the same effect. This feebleness in the evidence from symptoms, however, is of little moment; because the dose must be great to cause such symptoms, and little can be vomited before death; so that the poison will be certainly found in the stomach.
Should the patient die under symptoms of general irritation in the alimentary canal, poisoning may be suspected. But it would be impossible to derive from them more than presumptive evidence. The suspicion must become strong, however, if the ordinary signs of irritation in the alimentary canal are attended with the discharge of blood upwards and downwards. And the presumption will, I apprehend, approach very near to certainty,—at least of the administration of some active irritant poison,—if, at the moment of swallowing a suspected article, and but a short time before the symptoms of irritation began in the stomach and bowels, the patient should have remarked a strong, acrid, metallic taste, and constriction or burning in the throat.
When upon all these symptoms salivation is superinduced, the evidence of poisoning with corrosive sublimate or some other soluble salt of mercury is almost unequivocal. That is, if, after something has been taken which tasted acrid, and caused an immediate sense of heat, pricking, or tightness in the throat, the characteristic signs of poisoning with the irritants make their appearance in the usual time, and are soon after accompanied or followed by true mercurial salivation,—it may be safely inferred that some soluble compound of mercury has been taken. Before drawing this inference, however, it will be necessary to determine with precision all the classes of symptoms, more particularly the nature of the salivation. It should also be remembered that salivation may accompany or follow the symptoms of inflammation in the stomach, in consequence of calomel having been used as a remedy. But if proper attention be paid to the fallacies in the way of judgment, I conceive that an opinion on the question of poisoning with corrosive sublimate may be sometimes rested on the symptoms alone. This is another exception to the rule laid down by most modern toxicologists and medical jurists respecting the validity of the evidence of poisoning from symptoms.
For a good example of the practical application of these precepts, the reader may consult the trial of Mr. Hodgson, for attempting to poison his wife. In the instance which gave rise to the trial in question, a violent burning sensation in the throat was felt during the act of swallowing some pills; in the course of ten minutes violent vomiting ensued, afterwards severe burning pain along the whole course of the gullet down to the stomach, next morning diarrhœa, and on the third day ptyalism. There were many other points of medical evidence which left no doubt that corrosive sublimate was swallowed in the pills. But even the history of the symptoms alone would have led to that inference.[1012]
The morbid appearances observed in the bodies of persons killed by corrosive sublimate will not require many details; since most of the remarks formerly made under the head of the pathology of the irritants generally, and of arsenic in particular, apply with equal force to the present species of poisoning. Still there are some peculiarities deserving of notice, which arise from the greater solubility or stronger irritant action of corrosive sublimate.
The mouth and throat are more frequently affected than by arsenic; and a remarkable appearance sometimes observed, and not excited, so far as I know, by arsenic, is shrivelling of the tongue, with great enlargement of the papillæ at its root.[1013]
The disorder of the alimentary canal is also usually more general, and reaches a greater height before death takes place. Sometimes the irritation and organic injury are confined to the stomach;[1014] but more commonly the throat, stomach, gullet, rectum, nay, even also the colon, are affected. The black or melanotic extravasation into the mucous membrane of the stomach, which has been already several times described as a common effect of the more violent irritants, is also produced by corrosive sublimate. In Devergie’s case and in that of Dr. Venables it was present in a very great degree.[1015]
The coats of the stomach, and also those of the intestines, more particularly the colon and rectum, have frequently been found destroyed. So far as I have been able to ascertain, two kinds of destruction of the coats may be met with,—corrosion and ulceration.
The first is the result of chemical decomposition of the tissues. This kind is evidently to be looked for only when the quantity has been considerable and the dose concentrated. Nay even then it is rare. For on account of the solubility of corrosive sublimate, the facility with which it is decomposed by the secretions or accidental contents of the stomach, and the violence and frequency of the vomiting, this poison is peculiarly liable to be prevented from exerting its corrosive action on the membranes. Hence it is that proper chemical corrosion of the coats of the stomach is seldom witnessed in man.
The appearance of this corrosion differs according to the rapidity of the poisoning. In very rapid cases, for example in animals which have survived only twenty-five minutes, the villous coat has a dark gray appearance, without any sign of vital reaction.[1016] But this variety has never been witnessed in man, in whom the action has been hitherto much less rapid. In the most rapid cases, such as that of Dr. Bigsby, which terminated in two hours and a half (314), or those related by Mr. Valentine, of which one ended fatally in eleven and another in twenty-four hours, the corrosion was black, like the charring of “leather with a red-hot coal, and the rest of the stomach scarlet-red or deep rose-red;—showing that inflammation had set in.” In the former of these two cases the corrosion was as big as a half-crown, in the latter three inches in diameter. In a third case, where the patient lived thirty-one hours, the stomach was perforated.[1017] In the case described by Dr. Venables, and formerly alluded to, where life was prolonged for eight days, there was a patch on the under surface of the stomach as large as two crown-pieces, hard, elevated, and of a very dark olive or almost black colour, besides very general erosion of the villous coat.[1018] In all these cases the disintegrated spot was probably situated where the poison first chiefly lodged.
The corrosion caused by mercury, if examined before the slough is thrown off, will be found to possess an important peculiarity: the disorganized tissue yields mercury by chemical analysis. Professor Taddei repeatedly obtained the metal from the membranes of animals which he had poisoned with corrosive sublimate.[1019] It is probable that mercury may be thus detected although death may not have taken place for some time after the poison was swallowed. For the slough was found adhering in one of Mr. Valentine’s cases, where life was prolonged for seventy hours; and it was not entirely removed even in eight days in one of the cases described by Dr. Venables.
Although, however, it is sometimes possible to find the poison in the stomach, the medical jurist must not perhaps expect to find it so often in the present instance as in that of poisoning with arsenic. For on account of its greater solubility corrosive sublimate cannot adhere with such obstinacy to the villous coat, and is therefore more subject to be discharged by vomiting. Nevertheless, the insoluble compound formed by antidotes may adhere to the coats like arsenic, and so resist the tendency of vomiting to displace them. In Devergie’s case, notwithstanding twenty-three hours of incessant vomiting, although no poison could be detected in the fluid contents of the stomach, it was distinctly found in small whitish masses that lay between the folds of the rugæ.[1020]
It may be here farther observed that corrosive sublimate, as well as other salts of mercury, may undergo in the alimentary canal after death the same change which is produced in arsenic from the gradual action of hydrosulphuric acid gas. It may be converted into the sulphuret. I am not acquainted indeed with any actual instance of such conversion; but that it may occur we can scarcely doubt, not merely from theoretical considerations, but likewise because Orfila met with an instance where calomel taken daily in a case of gastro-cephalitis was discharged by stool in the form of a black sulphuret.[1021]
Another important consideration is, that corrosive sublimate may be decomposed and reduced to the metallic state by the admixture of various substances either given at the same time or subsequently, and the longer the inspection is delayed, the more complete will be the decomposition which is accomplished. Iron, zinc, and other metals are the most active of these substances.[1022]
The other forms of destruction of the coats of the alimentary canal is common ulceration, either such from the beginning, or what was originally corrosion converted into an ulcer in consequence of the disorganized spot being thrown off by sloughing.
I have seen this appearance to an enormous extent in the great intestines of a man who survived nine days. Numerous large, black, gangrenous ulcers, just like those observed in bad cases of dysentery, were scattered over the whole colon and rectum. In this instance, which occurred to the late Dr. Shortt, the stomach was also ulcerated, but the small intestines were not.
Sometimes the ulceration seems to be a variety of softening of the mucous tissue, as in a case described by Dr. Alexander Wood of this city, which proved fatal in fourteen days, and in which the stomach, cæcum, and ascending colon presented round, softened, greenish spots about the size of a sixpence, and accompanied in the stomach with a tendency to detaching of the membrane in the form of a slough.[1023]
The destruction of the villous coat of the stomach occasioned by corrosive sublimate and other soluble salts of mercury may be distinguished from spontaneous gelatinization by one of two characters. If the slough remains attached, mercury will be detected in it: if separation has taken place, the ulcer exposed presents surrounding redness and other signs of reaction.[1024]
All the other effects of inflammation may be produced by corrosive sublimate, as by arsenic and other irritants. More frequently here than in the case of arsenic peritonæal inflammation is met with. In Devergie’s case the external surface of the stomach along both its curvatures presented the appearance of red points on a violet ground. In Mr. Valentine’s cases there was much minute vascularity, not only of the outside of the stomach but also of the whole peritonæum lining the viscera and inside of the abdomen; and there was even some serous effusion into the cavity. In Dr. Venables’s case the peritonæal coat of the stomach was highly vascular and inflamed, and the omentum also injected.
The urinary organs, and particularly the kidneys, are often much inflamed by poisoning with corrosive sublimate. Dr. Henry has related a case in which this poison proved fatal on the ninth day, and where the left kidney was found to contain an abscess.[1025] In all of Mr. Valentine’s cases the kidneys were inflamed, and the bladder excessively contracted, so as not to exceed the size of a walnut. In Ollivier’s case, caused by the cyanide of mercury, the scrotum was gorged and black, the penis erected, and the kidneys a third larger than natural. In the case described by Dr. Venables both kidneys, but especially the left, were large, flaccid, and vascular, the ureters turgid and purple, and the bladder contracted, empty, and red internally.
Orfila has observed that the internal membrane of the heart is sometimes inflamed and checkered with brownish-black spots. Some remarks have been already made on the light in which this appearance ought to be viewed by the pathologist (p. 271).
Whatever may be the real state of the fact as to the alleged power of arsenic to preserve from decay the bodies of those poisoned with it, all authors agree that corrosive sublimate possesses no such property. Yet it is well known to be a good antiseptic, when applied topically. The experiments of Klanck, noticed under the head of Arsenic, prove that corrosive sublimate at all events does not retard putrefaction in the bodies of those poisoned with it; and Augustin in his analysis of Klanck’s researches infers that it even promotes decay.[1026] I have met with one example in the human subject which seems to confirm Augustin’s opinion. In the case formerly quoted from the Medical and Physical Journal, which was fatal in four days, the relater found the body forty-two hours after death so putrid, though in the month of January, that the examination of it was very unpleasant, the belly being black, and a very offensive odour being exhaled.[1027] Little importance, however, can be attached to a solitary case; for on the contrary Sallin relates a case where the body of a man supposed to have been poisoned with corrosive sublimate was found not decayed, but imperfectly mummified, after sixty-seven days.[1028]
It is unnecessary to detail the proofs to be found in the dead body of mercurial salivation having existed during life. They are of course to be looked for in the mouth, and in the adjoining organs. We must not, however, expect to see much appearance of disease in the salivary glands; for according to Cruveilhier, in persons who die of mercurial salivation these glands do not present any trace of inflammation themselves, but merely serous effusion into the cellular tissue around them.[1029]
Professor Orfila has made some useful experiments as to the effects of corrosive sublimate on dead intestine, which it may be proper to notice in a few words. When applied in the form of powder to the rectum of an animal newly killed, the part with which it is in contact becomes wrinkled, and as it were granulated, harder than natural, and of alabaster whiteness, intermingled with rose-red streaks, apparently the ramifications of vessels. When the membrane is stretched upon the finger, the wrinkling disappears. The muscular coat is of a snow-white colour, and even the serous coat is white, opaque, and thickened. The parts not in contact with the powder retain their natural appearance, and the line of demarcation between the affected and unaffected portions is abrupt. If the powder is not applied till twenty-four hours after death, the parts it touches become thick, white, and hard; but no red lines are visible. It is easy to draw the distinction between these appearances and the effects of corrosive sublimate during life.
Little need be said of the force of the evidence of poisoning with corrosive sublimate, derived from the morbid appearances. If the gullet, stomach, and colon be all inflamed and ulcerated, and these injuries have taken place during a short illness, the presumption in favour of some form of irritant poisoning will be strong. And the presumption of poisoning with corrosive sublimate will be strong, if the usual marks of salivation are also found in the mouth and throat. But such evidence can never amount to more than a strong presumption or probability.
The treatment of poisoning by the compounds of mercury may be referred to two heads,—that which is required when irritation of the alimentary canal is the prominent disorder, and that which is designed to remove mercurial salivation.
Irritation and inflammation of the alimentary canal are to be treated nearly in the same way as when arsenic has been the poison swallowed. In the instance of corrosive sublimate we also possess a convenient and effectual antidote.
Several substances may be used as antidotes; but those which have hitherto been most employed are albumen and gluten.
It has been already hinted that albumen, in the form of white of eggs beat up with water, impairs or destroys the corrosive properties of bichloride of mercury, by decomposing it and producing an insoluble mercurial compound. For this discovery and the establishment of albumen as an antidote, medicine is indebted to Professor Orfila. He has related many satisfactory experiments in proof of its virtues. The following will serve as an example of the whole. Twelve grains of corrosive sublimate were given to a little dog, and allowed to act for eight minutes, so that its usual effects might fairly begin before the antidote was administered. White of eight eggs was then given; after several fits of vomiting the animal became apparently free from pain; and in five days it was quite well.[1030] According to Peschier the white of one egg is required to render four grains of the poison innocuous.[1031] The experiments of the Parisian toxicologist have been repeated and confirmed by others and particularly by Schloepfer; who found that when a dose was given to a rabbit sufficient to kill it in seven minutes if allowed to act uncontrolled, the administration of albumen, just as the signs of uneasiness appeared, prevented every serious symptom.[1032] Dr. Samuel Wright has found that if the administration of albumen is followed up by giving some astringent decoction or infusion, the beneficial effects are more complete, because the compound formed is less soluble in an excess of albumen.[1033]
The virtues of albumen have also been tried in the human subject with equally favourable results. The recovery of the patient, whose case was quoted formerly (p. 312), from Orfila’s Toxicology, seems to have been owing in great measure to this remedy. In the Medical Repository another case is related, in which it Was also very serviceable.[1034] A third very apposite example of its good effects is related by Dr. Lendrick. His patient had taken about half a drachm of corrosive sublimate, and was attacked with most of the usual symptoms, except vomiting. White of eggs was administered a considerable time afterwards, the beneficial effects of which were instantaneous and well-marked; and the patient recovered.[1035] A few years ago Orfila’s discovery was the means of saving the life of M. Thenard the chemist. While at lecture, this gentleman inadvertently swallowed, instead of water, a mouthful of a concentrated solution of corrosive sublimate; but having immediately perceived the fatal error, he sent for white of eggs, which he was fortunate enough to procure in five minutes. Although at this time he had not vomited, he suffered no material harm. Without the prompt use of the albumen, he would almost infallibly have perished.[1036]
Albumen is chiefly useful in the early stage of poisoning with corrosive sublimate, and is particularly called for when vomiting does not take place. But it farther appears to be an excellent demulcent in the advanced stages.
On a previous occasion, mention was made of a few of the facts brought forward by Professor Taddei to prove the virtues of the gluten of wheat as an antidote for poisoning with corrosive sublimate [297, 336], so that nothing more need be said on the subject in the present place. As it is difficult to bring the whole of a fluid containing corrosive sublimate into speedy contact with pulverized gluten, which when put into water becomes agglutinated into a mass, the discoverer of this antidote proposes to give it in the form of emulsion with soft soap. This is made by mixing, partly in a mortar and partly with the hand, five or six parts of fresh gluten with fifty parts of a solution of soft soap. And in order to have a store always at hand, this emulsion, after standing and being frequently stirred for twenty-four hours, is to be evaporated to dryness in shallow vessels, and reduced to powder. The powder may be converted into a frothy emulsion in a few minutes.[1037] Taddei made use of this powder with complete success in the case of a man who had swallowed seven grains of corrosive sublimate by mistake for calomel. Violent symptoms followed the taking of the poison; but they were immediately assuaged by the administration of the antidote; and the person soon got quite well.[1038] It is probable that wheat flour will prove an effectual antidote by reason of the gluten it contains. On agitating for a few seconds a solution of twelve grains of corrosive sublimate along with three ounces of a strong emulsion of flour, and immediately filtering,—I find that ammonia and carbonate of potass have little or no effect, that hydriodate of potass occasions a yellow precipitate, and that the acrid, astringent taste of the solution is removed; whence it may be inferred, that the corrosive sublimate is all decomposed, that little mercury remains in solution, and that what does remain is in the form of a chloride of mercury and gluten.
When neither albumen nor gluten is at hand, milk is a convenient antidote of the same kind.
Iron filings would appear to be also a good antidote. MM. Milne-Edwards and Dumas have found that when they were administered in the dose of an ounce to animals after twelve or eighteen grains of corrosive sublimate had remained long enough in the stomach for the symptoms to begin, the animals recovered from the effects of the poison, and died only some days afterwards of the effects of tying the gullet, which operation was necessary to prevent them vomiting. The iron obviously acts by reducing the corrosive sublimate to the metallic state.[1039]
Meconic acid, the peculiar acid of opium, which will be described under the head of that poison, is also probably a good antidote. Pettenkoffer correctly remarks that this acid has a great tendency to form very insoluble salts with the metallic oxides, particularly with the deutoxides, and above all when the acid is previously in union with a base which constitutes a soluble salt.[1040] On this account it must be a good antidote. Pettenkoffer adds, that the precipitating action of the meconates is the reason why “the operation of corrosive sublimate on the animal body is almost entirely prevented by opium.” Opium, however, cannot be safely used in such quantity as to decompose all the corrosive sublimate in a case of poisoning; for I find that an infusion of thirty-three grains is required to precipitate all which can be thrown down from a solution of five grains of the mercurial salt. I am not aware of any instances on record where poisoning with corrosive sublimate has been prevented or cured by opium given so as to decompose the salt; but a very remarkable case will be related under the head of Compound Poisoning, where the phenomena of its action were masked and altered in a singular manner. There is little doubt that the alkaline meconates must prove valuable antidotes for corrosive sublimate. At present an effectual barrier to their employment is their rarity; but they might be rendered more accessible, as a great quantity of meconate of lime, which is at present put to no use, is formed in the manufacture of muriate of morphia; and meconate of potass may easily be prepared in sufficient quantity from the meconate of lime.
It has been alleged by Dr. Buckler of Baltimore, that a mixture of gold-dust and iron filings is an effectual antidote; but Orfila denies this statement; and the fact if true would be unimportant, on account of the improbability of the materials being ever at hand in practice.[1041]
M. Mialhe suggested not long ago as an antidote the proto-sulphuret of iron prepared by decomposing sulphate of protoxide of iron by hydrosulphate of ammonia; and Orfila found that it is a perfect chemical antidote, which altogether prevents the poisonous action of corrosive sublimate, if administered to animals either before or immediately after the poison; but he further ascertained that the lapse of ten minutes was sufficient to render it of no use.[1042] It is difficult, however, to perceive why in this respect it should differ from white of egg or any other chemical antidote.
As to the old antidotes for poisoning with corrosive sublimate, such as the alkaline carbonates, the alkaline hydrosulphates, cinchona, mercury, charcoal,—Orfila has given them all a fair trial, and found them all inefficacious. It would appear, however, from a case related in a late American journal, that frequent doses of charcoal powder have much effect in soothing the bowels and allaying the inflammation after the poison is evacuated.[1043]
The treatment of mercurial salivation consists in exposure to a cool pure air, nourishing diet, and purgatives, if the intestinal canal is not already irritated. In some of the inflammatory affections it induces, venesection is required; in others it is hurtful. In some complaints induced by mercury, as in iritis, the poison appears to be its own antidote; for nothing checks the inflammation so soon and so certainly as mercurial salivation.
Dr. Finlay of the United States proposed to check mercurial salivation by small doses of tartar emetic frequently repeated, so as to act on the skin;[1044] and Mr. Daniell has recommended large doses of the acetate of lead as an effectual antidote for the same purpose.[1045] I have tried both of these plans several times with apparent success. In one instance particularly, where a severe salivation was threatened by the administration of six grains of calomel in three doses, and where profuse salivation, ulceration of the tongue and swelling of the face actually did commence with violence, the mercurial affection after a few days rapidly receded under the use of large doses of acetate of lead.—Dr. Klose, a German physician, says he has found iodine to possess the property of arresting the effects of mercury on the mouth.[1046] The iodide of potassium is generally acknowledged to be one of the best remedies for eradicating the constitutional infirmities left in many by severe courses of mercury.
A great deal might be said on the treatment of the secondary effects of poisoning with mercury. But a thorough investigation of the subject would lead to such details as would be inconsistent with the other objects of this work.
Poisoning with the salts of copper was not long ago a common accident, in consequence of the metal being much used in the fabrication of vessels for culinary and other domestic purposes, or ignorantly resorted to by confectioners and others to impart a good colour to sweetmeats and preserves. Such accidents have been materially diminished in frequency since the poisonous qualities of the metal, and the circumstances under which it is acted on by articles of food, have become known. Nevertheless they are still frequent enough. The diffusion among the common people of the knowledge of the properties of copper has also naturally led some persons to have recourse to its preparations for the purpose of self-destruction. Poisoning with copper has seldom been caused by the wilful act of another person; for the deep colour of its compounds and their strong disagreeable taste render it a difficult matter to administer them secretly. This, however, though difficult, is not impossible: whatever may be swallowed accidentally, may be also administered secretly. In 1795 a woman Inglis was tried at Aberdeen for administering sulphate of copper with intent to poison; but the charge was not proved.[1047] In 1842 an attempt was made at Béziers in France to poison a young woman by dissolving this salt in her coffee; but the first mouthful caused such a sense of constriction in the throat as to apprize her of something deleterious being present, and she escaped after suffering from soreness of the mouth, vomiting and cramps.[1048] A case of imputed poisoning with sulphate of copper has been related at page 76.
Metallic copper has a special red colour, to which it gives its own name. Its specific gravity is nearly 9, its hardness considerable, its tenacity great, its point of fusion about 27° W. or at a full white heat.
It unites with oxygen in two proportions, forming a yellowish-red protoxide, and a peroxide, which, when dry, is brownish-black—when hydrated, azure-blue. It unites also with sulphur in two corresponding proportions, forming a gold-yellow proto-sulphuret, the natural copper-pyrites, and a black bisulphuret, which is formed by sulphuretted-hydrogen in all the solutions of this metal. The peroxide unites with ammonia. The acids all unite with the oxide and form blue or green salts, some of which are soluble, some insoluble. The oxide is frequently mixed with other matters to form various pigments; but in such compounds the union is generally mechanical, not chemical. Of the substances thus formed and existing in nature and the arts the following only require notice here. 1. Mineral green, and other pigments formed with the hydrated oxide. 2. Natural verdigris, or the carbonate. 3. Blue vitriol, or the sulphate. 4. Artificial verdigris, or the mixed acetates.
The description of this substance and its chemical properties must be introduced with a short account of the tests for the unmixed peroxide. When free of water the peroxide is a brownish-black powder or granular mass, which is usually procured by decomposing nitrate of copper at a low red heat. It is easily known by the solvent power of nitric acid, the blue colour of the filtered solution, and the beautiful deep violet tint communicated to the solution by an excess of ammonia. The last property is considered by chemists the most satisfactory proof of the presence of oxide of copper in a fluid. It is alone quite free of fallacy, and may be applied to all the soluble and also many insoluble compounds of copper, provided they are not mixed with a large proportion of vegetable or animal fluids, in which case the colour is often greenish.
In the case of the peroxide and of copper poisons generally, the process of reduction, which has been applied with such delicacy and precision to arsenical and mercurial poisons, loses all its advantages. The metal remains in the flux, and intimately diffused; so that of its physical qualities the colour only can be estimated, and even that but inaccurately, except in the instance of one compound, verdigris.
The hydrated peroxide of copper, when newly formed and well prepared, has a fine azure-blue colour; but on exposure to a gentle heat, it parts with its water, and becomes the anhydrous peroxide. It is procured by precipitating any of the soluble salts of copper by means of caustic potass. It is at once known by the action of ammonia, which immediately forms with it a deep violet-blue solution.
Mineral green, as already mentioned under the head of Arsenic (p. 223), was originally an arsenical pigment introduced into the art of colour-making by Scheele, and now sometimes sold in this country by the name of emerald-green. But the mineral green of the colourist now contains no arsenic, being a hydrate of peroxide of copper intimately mixed with a little lime, which is generally carbonated. This variety of mineral-green probably varies a little in composition. Some parcels I have found to contain the lime in the state of carbonate; in others the lime was chiefly caustic.
The best method of determining its nature is to dissolve it in diluted hydrochloric acid, which leaves only a slight cloudiness from accidental impurities; and then to transmit through the filtered solution a stream of sulphuretted hydrogen gas. The copper on boiling is all thrown down in the form of a black bisulphuret, and hydrochlorate of lime remains in solution. The lime is then to be detected by its proper tests, after the solution has been filtered and neutralized (see p. 192). In general this long process is unnecessary, as the medical jurist may be simply required to say whether the suspected substance contains copper. In that case it is only requisite to subject the substance to the action of ammonia, as if it was hydrated peroxide.
Verditer, another green pigment, the basis of which is always oxide of copper, does not appear to differ essentially in composition from mineral green. The samples I have examined consist of a large proportion of hydrated oxide of copper, and a small proportion of carbonate of lime.