Roger[874] experimented on the effect of copper leguminate which was administered subcutaneously; he found gradual increasing paralysis of the motor spinal tracts, which finally destroyed life by paralysis of the breathing centre. The heart beat after the breathing had stopped. The irritability and contractility of the muscles of frogs were lost, while sensibility remained. He also found that, if the copper was injected into the intestinal vessels, the dose had to be doubled in order to destroy life; this is, doubtless, because the liver, as it were, strained the copper off and excreted it through the bile. Roger was unable to destroy life by large doses of copper given by the mouth, for then vomiting supervened and the poison in great part was removed.
[874] Revue de Médecine, 1877, xii.
Bernatzic[875] considers that the poisonous properties of copper are similar to those of zinc and silver. He says: “Silver, copper, and zinc are, in their medicinal application, so much allied that, with regard to their action, they graduate one into the other and show only minor differences; copper, which is a little the more poisonous of the three so far as its remote action is concerned, stands between the other two. If taken, in not too small a quantity, for a long time, the functional activity of the muscular and nervous systems is influenced injuriously, the development of the animal cells is inhibited, the number of the red blood corpuscles decreased, and therefore the oxidising process and metabolism are likewise diminished, leading ultimately to a condition of marked cachexia. . . . From a toxic point of view, the three metals named also stand near each other, and their compounds differ from other metals injurious to the organism in this, that they do not produce notable changes of the tissues or coarse functional disturbances leading to death as other poisonous metals, and therefore are not to be considered poisons in the same sense as lead, mercury, arsenic, antimony, phosphorus are considered poisons; for, on stopping the entry of the poison, any injurious effect is completely recovered from and the functions again become normal.”
[875] Encycloped. d. ges. Heilkunde, xi. S. 429.
Lehmann[876] has also experimented on the effects of copper; his experiments were made on both animals and men. He found that small quantities were more thoroughly absorbed than medium or large doses; the method of separation appeared to be different in different animals—thus, the chief copper-excreting organ in dogs is the liver; in rabbits, the intestine; and in man, the kidneys. Of 3 mgrms. of copper taken by a man in three days, 1 mgrm., or a third, was recovered from the urine. Lehmann experimented on 6 rabbits, 4 cats, and 1 dog. During the first few days the animals were given 10 to 30 mgrms. of copper, in the form of a salt, in their food; then the dose was raised to 50 mgrms. or even to 100 mgrms., and the experiment continued for from two to four months; in one case, six months. The sulphate, acetate, chloride, oleate, butyrate, and lactate were all tried, but no essential difference in action discovered. Apart from slight vomiting, and in a few cases, as shown by post-mortem, a slight catarrh of the stomach, the animals remained well. A few increased in weight. Nervous symptoms, cramps, convulsions, diarrhœa, or the reverse, were not observed. The analysis of the organs showed considerable copper absorption; the liver of the cats gave a mean amount of 12 mgrms. of copper, and in the other organs there was more copper than is found in cases of acute poisoning.