In the metallic state, copper is quite inert. Instances are on record in which copper coins have remained long in the stomach without any observable effect; and animals which have been made to swallow filings of the metal, to the amount even of an ounce, have in no degree sensibly suffered from them. Yet other cases have occurred, in which local injury to the stomach, or some derangement of the system has followed under similar circumstances. The result in these instances has, no doubt, depended on chemical changes, by which the metal has been oxidized, and converted into a salt through the agency of the gastric acids; so that it was not the copper itself, but one of its soluble compounds, probably the chloride, that acted.

Copper may generally be detected in minute quantities in the blood of persons in health, and has been repeatedly found in the tissues, when no preparation of the metal was known to have been taken. It has hence been inferred that, like iron, it forms an essential constituent of the blood; and Millon supposed it to enter into the normal constitution of the red corpuscles. But so much copper is taken into the system in various ways with our food, that the exceedingly minute portion which a delicate chemical analysis can detect, has its origin probably in this source, and is only accidentally present in the blood, which would in no degree suffer from the want of it, as it does from the want of iron. Wackenroder has confirmed this view by showing that the blood of domestic animals, living on pure vegetable food, is quite destitute of it : while it may readily be discovered in the blood of the same animals and of man, when fed on a mixed diet. (Chem. Gaz., May 1, 1854, p. 175.) It may be inferred, however, from these facts, that a proportion of cop-per large enough to be sensible to chemical research, may exist in our economy without impairing health.

Effects on the System

The preparations of copper are locally irritant, and most of them, in a concentrated state, corrosive. Taken internally, in moderate doses, they operate as gentle excitants to the mucous surface of the stomach, increasing the appetite, and producing other effects characteristic of tonic medicines. In over-doses they become irritant; but happily provoke vomiting very promptly; so that, being discharged from the stomach, they have not time allowed them to produce serious and permanent effects, unless taken very largely. In this latter event, as will be seen directly, they are capable of producing fatal inflammation and corrosion of the alimentary mucous membrane. Like nitrate of silver, they decompose the superficial parts of the tissue, forming compounds with albumen, which are of a greenish-blue colour, and, according to Mialhe, soluble in an excess of the salt, when its acid is of vegetable origin, but not when it is mineral.

But the preparations of copper also act on' the system generally. This they are enabled to do by the facility with which they enter the circulation. They appear, indeed, to be among the metallic substances most easily absorbed. After one of the salts of copper has been taken for a short time, the metal may be sought for in vain in the alimentary canal, but will be found in the blood, the substance of the liver, and other tissues. When absorbed, moreover, it holds its place in the organism with great tenacity. Orfila states that it may be detected in the liver, intestinal coats, and bones, eight months after having been taken into the stomach. (Lond. Med. Times and Gaz., March, 1852, p. 279).

No observable effects upon the system, in health, are produced by small medicinal doses of the salts of copper; but the results of their use in disease prove that, even in these quantities, they are not without efficiency. Their action appears to be that of a tonic, especially on the nervous centres, which they strengthen against irritating influences, as explained in the general observations on this subdivision of mineral tonics. (See page 388.) When taken too largely, or too long, they give unmistakable evidence of their effects, which may even be poisonous, independently of their direct action on the alimentary mucous membrane.

The poisonous operation of the salts of copper is of two kinds, either rapid from a large quantity given at once, or slow from too long a continuance of relatively small quantities. In both of these modes of action. moreover, there appears to be a union of a local influence on the mentary mucous membrane, with a general influence dependent on absorption.

1. Acute poisoning from a large quantity is attended with a coppery taste in the mouth, nausea, incessant vomiting, violent pains in the stomach and bowels, purging sometimes profuse, severe headache, cramps in the lower extremities, and, in fatal cases, convulsions, palsy of the limbs, and coma. In the lower animals, Orfila noticed, among the last phenomena before death, rigidity of the muscles, and oven tetanus. Occasional salivation is also mentioned; and jaundice is not uncommon, generally appearing during life, but sometimes not until after death. The first series of the symptoms here detailed are evidently the direct result of the irritant action on the stomach and bowels; those which succeed depend on a systemic influence directed more especially to the nervous centres, but sometimes exerted on the salivary glands, and not unfre-quently upon the blood, as evinced by the jaundice, which probably arises from the destruction of the red corpuscles, and the alteration of their colouring matter. That the nervous symptoms are not merely sympathetic with the gastric disorder is proved by the facts, first, that after death the mucous membrane of the stomach and bowels is, in some instances, found to all appearance quite healthy, especially after speedy death; secondly, that the nervous symptoms sometimes precede the gastric and intestinal, and thirdly, that similar phenomena have resulted from the poison injected into the veins, or applied to a wounded surface. The ordinary post-mortem phenomena are signs of severe inflammation in the stomach and bowels, gangrenous patches here and there, corrosion and sometimes even perforation of the intestinal mucous membrane, and green discoloration of the tissue to a greater or less extent. The lungs are said also to have been seen inflamed; but this may have been an accidental coincidence.

2. The slow poisoning, according to Dr. Corrigan, of Dublin, who has drawn up his summary from an observation of several cases, is attended with emaciation, a cachectic appearance, muscular weakness, colicky pains, cough without discoverable pectoral disease, "and a peculiar characteristic retraction of the gums, with a purple, not a blue edge;" without the severe colic, constipation, and local palsy, which result from lead. (Braithwaite, xxx. 303, from Dub. Hosp. Gaz., Sept. 1853, p. 232.)* Besides these phenomena, loss of appetite and diarrhoea are mentioned by other observers. I have seen no account of death from this slow poisoning. The symptoms are probably due partly to a chronic irritation of the alimentary canal, partly to a direct action upon the system.

* In July, 1855, Dr. Pietra-Santa, who had been favourably situated for observing the effects of copper on the system, read a memoir before the Academy of Medicine of Paris, in which he stated that, after three years of observation, he had come to the following conclusions; - "1. that a person may live in an atmosphere loaded with the dust of copper, without any appreciable alteration of health; 2. that the introduction of powder of copper into the stomach occasions only some slight disturbances of health; 3. that the colic of copper, as previously described by authors, does not exist; 4. that the phenomena described by authors must be attributed to other contemporaneous causes; and 5. that the purple edging of the gums, mentioned by Dr. Corrigan as characteristic of copper poisoning, is not so constant or general as he supposes." (Arch. Gen., 5e se"r., vi. 354; and Journ. de Pharm. et de Chim., Avril, 1858, p. 313.) - Note to the second edition.

A case of copper-colic, with the stain on the gums as described by Dr. Corrigan, is reported by Dr. Harley, whose patient was a copper-plate printer, and had on one occasion been peculiarly exposed to the inhalation of one of the salts of copper, while cleaning some old plates, from which a dust arose like verdigris. He had suffered twice before in the same way. The symptoms were a sudden and violent pain in the abdomen as if from a blow, somewhat abating and increasing, augmented by pressure rather than diminished, no diarrhoea, and no constipation. There was a sallow, almost clay-coloured complexion, with anxious expression, livid lips, and sunken eyes. He rapidly recovered under the use of spirit of nitric ether, and dilute sulphuric acid, with a little sulphate of magnesia and laudanum, taken in camphor mixture. (Med T. and Gaz., Aug. 1863, p. 129.) It is difficult to reconcile these opposite observations of Drs. Pietra-Santa and Harley, unless upon the supposition, that the "dust of the copper" of the former was the metal itself in a state of minute division; while the powder, which was the poisonous agent in the case described by the latter, consisted of a salt of the metal. The uncombined metal is innoxious, while its saline compounds may be extremely poisonous. (Note to the third edition).

Poisoning by copper sometimes results from the accidental swallowing of one of its preparations used in medicine or the arts, but more frequently from food or drink prepared or kept in copper vessels, which, even though protected by tinning, are nevertheless apt to lose this protection, and to communicate deleterious properties to substances contained in them, especially when these substances are in any degree acid. There is reason to believe that much injury has thus been produced in the digestive organs, if not in the general system, by the habitual use of carbonic acid water, prepared and long kept in copper fountains.

The treatment of the acute poisoning consists mainly in the free use of the white of egg mixed with water, which forms an insoluble compound with the poison, and at the same time facilitates the cleansing of the stomach. Should this not be at hand, recourse may be had to milk, or even wheat flour mixed with water. Ferrocyanide of potassium has also been recommended as an antidote; but, according to results obtained by Dr. Scharder, of Gottingen, it must be considered of doubtful efficacy. Hydrated protosulphuret of iron, recommended by Murine, hydrate of magnesia, and sugar, proved inefficacious in the hands of the same experimenter. (Deutsche Klinik, 1855, No. 4.) Should free emesis not take place, the stomach should be thoroughly washed out by the stomach-pump. Afterwards the antidote should be administered with a cathartic, in order that it may reach any portion of the poison that may have entered the bowels. The irritation of the stomach and bowels may then be quieted by opiates; and the case otherwise treated on general principles.

The therapeutic applications of copper will be most conveniently treated of, under the heads of its several preparations.