Chapter IV · METALLIC IRRITANTS (continued 2)

Copper poisoning may result from—

1. Its introduction into the system by using, for culinary purposes, copper vessels not properly tinned. An interesting account of poisoning from this source may be found in the second volume of the Medical Observations and Inquiries by a Society of Physicians in London, published 1764. The cases there recorded occurred on board ship, with most alarming symptoms.

2. By constant application of the metal to the surface of the body, necessitated by certain processes in its manufacture and in its application for industrial purposes. M. Michel Levy, however, says in his work, Traité d‘Hygiène, Publique et Privée, that workmen in copper may pass green-coloured urine and yet be as robust and as long-lived as other workmen.

3. The use of certain preparations of this metal as pigment.

4. The use of German silver—an alloy of copper, zinc, and nickel—may be rendered dangerous by the action of acid food upon the compound.

5. The use of a salt of copper to give a green fresh colour to certain tinned vegetables and fruits, peas, &c., now introduced into this country from France.

Post-mortem Appearances.—The mucous membrane of the stomach is inflamed, the inflammation extending sometimes into the gullet. The intestines may be found perforated. The lining membrane of the whole alimentary canal presents a deep green colour, distinguished from that the result of a morbid condition of the bile by being turned blue on the addition of ammonia.

Fatal Dose.—Nothing certain is known as to the exact quantity that may prove fatal, as the evidence of the poisonous action of copper is somewhat contradictory. It appears to be more dangerous in small doses than in large ones. Half an ounce of verdigris or subacetate has proved fatal to an adult.

Fatal Period.—The shortest time on record is four hours.

Treatment.—Induce vomiting, and assist the emetic action of the copper salts by the free use of warm water, milk, or any demulcent drink. The stomach tube may be used if vomiting does not occur. As an antidote, large quantities of albumen and iron filings have been given, of which the former appears to be most efficacious.

Chemical Analysis.—The following are the liquid tests for copper in solution:—

1. Ammonia gives a bluish-white precipitate soluble in excess, forming a blue solution.

2. Sulphuretted hydrogen and ammonium sulphide give a chocolate-coloured precipitate.

3. Ferrocyanide of potassium gives a port-wine colour, or reddish-brown precipitate.

4. If a bright steel needle be introduced into an acid solution of copper, the metal is deposited on the needle.

5. If a piece of zinc bound with platinum wire be placed in a solution of a copper salt, the metal is deposited on the platinum; it is turned violet on exposure to the vapour from sulphuric acid mixed with potassium bromide.

Detection of Copper in Organic Liquids

A.—The finely-divided tissue, or the contents of the stomach, diluted with water, are thrown on a filter, and the insoluble portion set aside for further treatment. (See B.)

The filtrate and washings may now be concentrated, acidified with sulphuric acid, and a polished needle inserted in the liquid; and should no immediate deposition of metallic copper occur, it may be allowed to remain for several hours. The colour of the metallic deposit is highly characteristic of copper. As a corroborative proof, the concentrated liquid may be placed in a platinum capsule with some fragments of zinc, when the copper will be deposited on the platinum capsule at the parts in contact with the zinc; the liquid poured off, and the excess of zinc adhering to the platinum removed by dilute hydrochloric acid. The copper may now be dissolved off the platinum by nitric acid, the excess of acid driven off by heat, and the solution subjected to the wet tests given above.

B.—The insoluble portion from A is incinerated in a porcelain crucible. The ash thus obtained is digested in hydrochloric acid with the aid of heat, and evaporated nearly to dryness. The residue, dissolved in distilled water, may be tested as under ‘A.’

ZINC

The sulphate and the chloride of zinc are alone important. Poisoning by the chloride of zinc has been described (p. 265).

Sulphate of Zinc

White vitriol or white copperas.

Symptoms.—The sulphate of zinc acts as a pure irritant. Violent vomiting, accompanied with pain in the abdomen, and purging, are the symptoms which first make their appearance. These may be followed by symptoms which betoken collapse, viz. coldness of the limbs, paleness of the face, irregular pulse, and fainting.

Post-mortem Appearances.—Presence of inflammatory action.

Fatal Dose.—Uncertain.

Fatal Period.—Death has occurred in four hours.

Chemical Analysis.—Distinguished from oxalic acid by remaining fixed when heated on platinum foil.

In Solution:

1. Ammonia gives a white precipitate soluble in excess.

2. Ferrocyanide of Potassium, a white precipitate.

3. Sulphuretted Hydrogen or Ammonium Sulphide, a milky-white precipitate in a neutral pure solution.

4. Nitrate of Baryta, a white precipitate showing the presence of sulphuric acid.

5. Caustic potash or soda, a white precipitate soluble in excess.

In Organic Mixtures pass sulphuretted hydrogen, collect the sulphuret, and decompose it with boiling hydrochloric acid, then test for zinc.

Treatment.—Tea, coffee, milk, warm water, albumen, and in some cases enemata of gruel and other emollients.

IRON

The preparations of iron which are of importance are the sulphate and the muriate.

Sulphate of Iron

Copperas or Green Vitriol—has been administered as a poison, but more frequently to procure abortion. An ounce has been taken with no other serious effect than the production of violent pain, purging, and vomiting. Constant application of this substance to the body has produced vomiting, pains in the belly and limbs. These symptoms disappear on treatment.

Chemical Analysis.—(1) Hydrosulphuret of ammonia gives a black precipitate. (2) Ferrocyanide of potassium added to it, in solution, gives rise to a greenish-blue precipitate, becoming dark blue on exposure. (3) Chloride of barium will point to the nature of the acid present.

Muriate of Iron

Better known as the Tincture of Sesquichloride of Iron, or the Tinctura Ferri Perchloridi.—The tincture acts as a corrosive and irritant poison, death having followed in five weeks after an ounce and a half had been swallowed. It is sometimes used as an abortifacient. Recovery has, however, taken place after three ounces had been swallowed. The symptoms present in most cases observed were those of a corrosive and irritant.

Chemical Analysis.—(1) The addition of nitrate of silver, causing a white precipitate insoluble in nitric acid, points to the presence of chlorine. (2) The peroxide of iron, indicated by the formation of Prussian blue on adding a solution of the ferrocyanide of potassium.

BISMUTH

The preparations of this metal act as irritant poisons, death having occurred from a dose of two drachms of the sub-nitrate. Dr. Trail (Outlines of Medical Jurisprudence, p. 116) mentions the ease of a patient of his who took six drachms in three days in divided doses. The symptoms were vomiting, extreme pain in the abdomen and throat, a weak, feeble pulse, and much anxiety about the præcordia. Recovery took place. A case of severe vomiting during pregnancy, ending fatally, was mistaken for arsenic poisoning. The error arose from mistaking a greyish powder on the walls of the stomach for arsenic. It turned out on further inquiry that it was bismuth, given medicinally to prevent the vomiting. Bismuth carbonate mixed with gruel or bread and milk is given in large quantities for the purposes of radiography of the alimentary canal without any untoward effects.

POTASSIUM

Nitrate of Potash

This substance is well known as nitre, saltpetre, and sal prunella. In large doses it acts as an irritant, and cases are recorded in which it has been used to poison children. In one case, the presence of crystals of the salt in some of the dried vomited matter on the child‘s shoe, led to an explanation of the cause of death.

Symptoms.—Those of a pure irritant, to which death must be referred, and not to any constitutional action of the drug. The nervous symptoms, which are sometimes very marked, are, as is well known, common to the action of many pure irritants. In some cases there is suppression of urine.

Post-mortem Appearances.—Those produced by irritants generally.

Chemical Analysis.—Separate the poison by dialysis, evaporate, and test the crystals as directed under nitric acid.

Fatal Dose.—About an ounce.

Fatal Period.—Two hours.

Treatment.—The same as for other irritants; demulcent drinks. Promote vomiting.

Sulphate of Potash

Sal Polychrist, Sal de Duobus, or sulphate of potash, acts as an irritant poison, being largely used in France as an abortive. The symptoms and the post-mortem appearances are much the same as those produced by the nitrate. A like treatment may also be adopted. In the detection of this substance, the nitrate of baryta will point to the acid present, and bichloride of platinum to the presence of potash.

Chlorate of Potash

This salt acts as a poison when taken in large doses, producing symptoms which might be mistaken for poisoning with arseniuretted hydrogen, or for such diseases as hæmoglobinuric fever.

Symptoms.—These comprise pain in the stomach and bowels with vomiting, collapse and stupor, cyanosis, jaundice; diminution of the urine, which contains hæmoglobin, casts, and albumen. It is a question whether the jaundice is hæmatogenous or hepatogenous. Chlorate of potash destroys the red corpuscles, the hæmoglobin is dissolved out and is set free in the liquor sanguinis.

Fatal Dose.—45-50 grains proved fatal to a child three years old. For an adult 390 grains to an ounce and a half.

Fatal Period.—From five hours to several days.

Treatment.—The stomach should be washed out through the syphon tube. Venæsection may be useful, with subsequent transfusion of fresh blood. The nephritis and other symptoms must be treated generally.

Post-mortem Appearances.—The mucous membrane of the stomach may be inflamed and submucous hæmorrhages may be found. The blood is chocolate in colour and gives the spectrum of methæmoglobin. The spleen is enlarged and chocolate-coloured, and the kidneys acutely inflamed.

Chemical Analysis.—Chlorate of potash may be separated from organic material by dialysis.

1. If to a solution of the salt a few drops of indigo sulphate be added, and then a few drops of strong sulphuric acid, the indigo-blue is bleached.

2. If a small crystal of the chlorate be heated in a test tube with a drop of strong sulphuric acid, it explodes with detonation.

BARIUM

The chloride, nitrate, and carbonate of barium are all irritant poisons. But besides their irritant action, the salts of barium also appear to act on the nervous system and the heart, arresting its action in systole. The symptoms, post-mortem appearances, and treatment are the same as for the other irritant poisons. Sulphate of magnesia, or other soluble sulphate, should be given to form an insoluble sulphate of baryta. Sulphate of barium is also used like bismuth carbonate for radiography.

Chemical Analysis.—Sulphuric acid or alkaline sulphate gives a white precipitate with solution of chloride of baryta, insoluble in nitric acid. The salts impart to flame a greenish-yellow colour. The chlorine is detected by nitrate of silver. Dissolve the carbonate in hydrochloric acid, and test as above.

CHROMIUM

Two compounds of this metal are largely used in the arts for dyeing purposes—the neutral chromate and the acid bichromate of potash. The bichromate of potash is a powerful poison, and death may occur from its direct action on the nervous system, without the development of any of the signs of irritation; in other cases, however, well-marked irritant symptoms have been present. Applied externally, it produces deep fistulous sores, especially on the mucous membrane of the septum of the nose, in the workmen who are engaged in its manufacture. These sores are prevented to some extent by taking snuff. Dyers not infrequently suffer severely on their arms when using it in the course of their trade. Death has resulted in four hours after its administration.

Chemical Analysis.—A solution of the bichromate of potash, added to a solution of acetate of lead, gives a yellow precipitate; with nitrate of silver, a red. The salt boiled with hydrochloric or sulphuric acid and alcohol, gives a green liquid.

Treatment.—Emetics, magnesia, chalk, demulcent drinks, &c.