COPPER
Metallic copper, like metallic lead, is not poisonous, but its oxides are; it should, therefore, not be swallowed, as it is rapidly acted on by the intestinal secretions and poisonous compounds formed. An alloy of copper is used for ornamenting ginger-bread, &c. All the salts of copper are poisonous. The most important are, however, the sulphate, blue-stone, or blue vitriol, and the subacetate or verdigris.
Copper is eliminated to a slight extent by the urine. It has been found in the stomach, liver, and intestines eight months after its administration had been discontinued. It has also been detected more readily in the bronchial secretion than in the urine.
Symptoms of Poisoning by Copper
Acute.—The primary action of the sulphate of copper in from five- to fifteen-grain doses is that of a quick emetic; in larger doses, a powerful irritant; but when absorbed, it appears to act chiefly on the brain and nervous system. Its irritant action is marked by nausea, vomiting, griping pain in the belly, which is greatly distended, and increased flow of saliva. The vomited matters are of a bluish or greenish colour, and the discharges from the bowels greenish and containing blood. The vomited matters become blue on the addition of ammonia. The above-mentioned symptoms usually follow immediately after the poison is swallowed, and rapidly increase in severity. After a time, the remote effects supervene, marked by headache, giddiness, laboured breathing, quick irregular pulse, coma or convulsions, paralysis, and death.
In poisoning by this substance, the convulsions are most violent, and wild incoherent delirium not infrequent.
The subacetate of copper or verdigris produces symptoms not unlike those just described. Jaundice and suppression of urine may result when either this or the sulphate is taken.
Chronic.—Constant and troublesome irritation of the stomach and bowels; vomiting and purging, attended with considerable straining at stool; loss of appetite, loss of power, and general emaciation set in. The patient is subject to frequent trembling of the limbs, which may end in paralysis. The mouth is unpleasant, and a coppery, metallic taste is experienced. Cramps or colicky pains in the belly are not infrequently present. Jaundice is sometimes present. The vomited matters are greenish; but the practitioner must not be led away, and thus mistake the colour of the vomited matters which occur in some morbid states of the bile, for the result of poisoning by a salt of copper. A form of chronic poisoning affecting workers in this metal has been described by some French pathologists as “copper-colic.” A cachectic condition of the system, accompanied with one or more of the symptoms already detailed, marks this form of poisoning. A purple line along the margins of the gums is present in some cases.
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.’