[Footnote: Read before the Medico Legal Society, April 5, 1883.]

By HENRY A. MOTT, JR., Ph.D., etc.

Of the various salts of silver, the nitrate, both crystallized and in sticks (lunar caustic, Lapis infernalis), is the only one interesting to the toxicologist.

This salt is an article of commerce, and is used technically and medicinally.

Its extensive employment for marking linen, in the preparation of various hair dyes (Eau de Perse, d'Egypte, de Chiene, d'Afrique), in the photographer's laboratory, etc., affords ample opportunity to use the same for poisoning purposes.

Nitrate of silver possesses an acrid metallic taste and acts as a violent poison.

When injected into a vein of an animal, even in small quantities, the symptoms produced are dyspnoea,[1] choking, spasms of the limbs and then of the trunk, signs of vertigo, consisting of inability to stand erect or walk steadily, and, finally retching and vomiting, and death by asphyxia. These symptoms, which have usually been attributed to the coagulating action of the salt upon the blood, have been shown not to depend upon that change, which, indeed, does not occur, but upon a direct paralyzing operation upon the cerebro-spinal centers and upon the heart; but the latter action is subordinate and secondary, and the former is fatal through asphyxia.

[Footnote 1: Nat. Dispensatory. Alf. Stille & John M. Maisch, Phila., 1879, p. 232.]

One-third of a grain injected into the jugular vein killed a dog in four and one-half hours, with violent tetanic spasms.[1]

[Footnote 1: Medical Jurisprudence. Thomas S. Traill, 1857, p 117.]

Devergie states that acute poisoning with nitrate of silver, administered in the shape of pills, is more frequent than one would suppose. Yet Dr. Powell[1] states that it should always be given in pills, as the system bears a dose three times as large as when given in solution. The usual dose is from one-quarter of a grain to one grain three times a day when administered as a medicine. In cases of epilepsy Dr. Powell recommends one grain at first, to be gradually increased to six. Clocquet[2] has given as much as fifteen grains in a day, and Ricord has given sixteen grains of argentum chloratum ammoniacale.

[Footnote 1: U.S. Dispensatory, 18th ed., p. 1049. Wood & Bache.]

[Footnote 2: Handbuch der Giftlehre, von A. W. M. Von Hasselt. 1862, p. 316.]

Cases of poisoning have resulted from sticks of lunar caustic getting into the stomach in the process of touching the throat (Boerhave)[1]; in one case, according to Albers, a stick of lunar caustic got into the trachea.

[Footnote 1: Virchow's Archiv, Bd. xvii., s. 135. 1859.]

Von Hasselt therefore urges the utmost caution in using lunar caustic; the sticks and holder should always be carefully examined before use. An apprentice[1] to an apothecary attempted to commit suicide by taking nearly one ounce of a solution of nitrate of silver without fatal result. It must be remarked, however, that the strength of the solution was not stated.

[Footnote 1: Handbuch der Giftlehre, von A. W. M. Von Hasselt. Zweiter Theil, 1862. p. 316.]

In 1861, a woman, fifty-one years old, died in three days from the effects of taking a six-ounce mixture containing fifty grains of nitrate of silver given in divided doses.[1] She vomited a brownish yellow fluid before death. The stomach and intestines were found inflamed. It is stated that silver was found in the substance of the stomach and liver.

[Footnote 1: Treatise on Poison. Taylor, 1875, p. 475.]

It is evident that the poisonous dose, when taken internally, is not so very small, but still it would not be safe to administer much over the amounts prescribed by Ricord, for in the case of the dog mentioned one third of a grain injected into the jugular vein produced death in four and one-half hours.

The circumstance that more can be taken internally is explained by the rapid decomposition to which this silver salt is liable in the body by the proteine substance and chlorine combinations in the stomach, the hydrochloric acid in the gastric juice, and salt from food.

The first reaction produced by taking nitrate of silver internally is a combination of this salt with the proteinaceous tissues with which it comes in contact, as also a precipitation of chloride of silver.

According to Mitscherlich, the combination with the proteine or albuminous substance is not a permanent one, but suffers a decomposition by various acids, as dilute acetic and lactic acid.

The absorption of the silver into the system is slow, as the albuminoid and chlorine combinations formed in the intestinal canal cannot be immediately dissolved again.

In the tissues the absorbed silver salt is decomposed by the tissues, and the oxide and metallic silver separate.

Partly for this reason and partly on account of the formation of the solid albuminates, etc., the elimination of the silver from the body takes place very slowly. Some of the silver, however, passed out in the faeces, and, according to Lauderer, Orfila, and Panizza, some can be detected in the urine.

Bogolowsky[1] has also shown that in rabbits poisoned with preparations of silver, the (often albuminous) urine and the contents of the (very full) gall bladder contained silver.

[Footnote 1: Arch. f. Path. Anatomie, xlvi., p. 409. Gaz. Med de Paris, 1868, No. 39. Also Journ. de l'Anatomie et de la Physiologie, 1873, p. 398.]

Mayencon and Bergeret have also shown that in men and rabbits the silver salt administered is quickly distributed in the body, and is but slowly excreted by the urine and faeces.

Chronic poisoning shows itself in a peculiar coloring of the skin (Argyria Fuchs), especially in the face, beginning first on the sclerotic. The skin does not always take the same color; it becomes in most cases grayish blue, slaty sometimes, though, a greenish brown or olive color.

Von Hasselt thinks that probably chloride of silver is deposited in the rete malpighii, which is blackened by the action of light, or that sulphide of silver is formed by direct union of the silver with the sulphur of the epidermis. That the action of light is not absolutely necessary, Patterson states, follows from the often simultaneous appearance of this coloring upon the mucous membrane, especially that of the mouth and upon the gums; and Dr. Frommann Hermann[1] and others have shown that a similar coloring is also found in the internal parts.

[Footnote 1: Leh der Experiment. Tox. Dr. Hermann, Berlin, 1874, p. 211.]

Versmann found 14.1 grms. of dried liver to contain 0.009 grm. chloride of silver, or 0.047 per cent. of metallic silver. In the kidneys he found 0.007 grm. chloride of silver, or 0.061 per cent. of metallic silver; this was in a case of chronic poisoning, the percentage will be seen to be very small. Orfila Jun. found silver in the liver five months after the poisoning.

Lionville[1] found a deposit of silver in the kidneys, suprarenal gland, and plexus choroideus of a woman who had gone through a cure with lunar caustic five years before death.

[Footnote 1: Gaz. Med., 1868. No. 39.]

Sydney Jones[1] states that in the case of an old epileptic who had been accustomed to take nitrate of silver as a remedy, the choroid plexuses were remarkably dark, and from their surface could be scraped a brownish black, soot-like material, and a similar substance was found lying quite free in the cavity of the fourth ventricle, apparently detached from the choroid plexus.

[Footnote 1: Trans. Path. Soc., xi. vol.]

Attempts at poisoning for suicidal purposes with nitrate of silver are in most cases prevented from the fact that this salt has such a disagreeable metallic taste as to be repulsive; cases therefore of poisoning are only liable to occur by accident or by the willful administration of the poison by another person.

Such a case occurred quite recently, to a very valuable mare belonging to August Belmont.

I received on Dec. 6, 1882, a sealed box from Dr. Wm. J. Provost, containing the stomach, heart, kidney, portion of liver, spleen, and portion of rectum of this mare for analysis.

Dr. Provost reported to me that the animal died quite suddenly, and that there was complete paralysis of the hind quarters, including rectum and bladder.

The total weight of the stomach and contents was 18 lb., the stomach itself weighing 3 lb. and 8 oz.

Portions were taken from each organ, weighed, and put in alcohol for analysis.

The contents of the stomach were thoroughly mixed together and measured, and a weighed portion preserved for analysis.

The stomach, when cut open, was perfectly white on its inner surface, and presented a highly corroded appearance.

The contents of the stomach were first submitted to qualitative analysis, and the presence of a considerable quantity of nitrate of silver was detected.

The other organs were next examined, and the presence of silver was readily detected, with the exception of the heart!

The liver had a very dark brown color. A quantitative analysis of the contents of the stomach gave 59.8 grains of nitrate of silver. In the liver 30.5 grains of silver, calculated as nitrate, were found (average weight, 11 lb.). From the analysis made there was reason to believe that at least one-half an ounce of nitrate of silver was given to the animal. Some naturally passed out in the faeces and urine.

I was able to prepare several globules of metallic silver, as also all the well known chemical combinations, such as sulphide, chloride, oxide, iodide, bromide, bichromate of silver, etc.

From the result of my investigation I was led to the conclusion that the animal came to death by the willful administering of nitrate of silver, probably mixed with the food.

The paralysis of the hind quarters, mentioned by Dr. Provost, accords perfectly with the action of this poison, as it acts on the nerve centers, especially the cerebro-spinal centers, and produces spasms of the limbs, then of the trunk, and finally paralysis.

I might also state in this connection that, only two weeks previous to my receiving news of the poisoning of the mare, I examined for Mr. Belmont the contents of the stomach of a colt which died very mysteriously, and found large quantities of corrosive sublimate to be present.

Calomel is often given as a medicine, but not so with corrosive sublimate, which is usually employed in the arts as a poison.

It is to be regretted that up to the present moment, even with the best detectives, the perpetrator of this outrage has been at large. Surely the very limit of the law should be exercised against any man who would willfully poison an innocent animal for revenge upon an individual. Cases have been reported in England where one groom would poison the colts under the care of another groom, so that the owner would discharge their keeper and promote the other groom to his place.

A few good examples, in cases where punishment was liberally meted out, would probably check such unfeeling outrages.