for Drouard gave an ounce to dogs without injuring them at all,[1] and Lefortier more lately observed that two drachms had no effect.[2] The same explanation must be given of the injury sustained by those artisans who prepare and use what is called "bronze dust" in printing and paper-staining. If the substance employed be nothing else than an alloy of copper and zinc, as is alleged, the injurious effects to be mentioned presently can only be explained on the supposition that the copper becomes oxidated either before or after coming in contact with the body. It deserves to be added, that many persons have swallowed copper coins and retained them for weeks without having any symptoms of poisoning.
The sulphuret is equally innocuous with the metal if pure; but it appears probable that it becomes oxidated by long exposure to the air, and passes into the state of sulphate. Orfila found that an ounce of recently prepared sulphuret had no effect on a dog; but half an ounce of a parcel which had been long kept caused vomiting, and yielded a little sulphate to water.[3] The power of the oxides has not been ascertained. They are certainly poisonous; and Lefortier found that both the red ditoxide and black protoxide undergo solution in no long time in the stomachs of dogs.[4] The hydrated protoxide is probably more active. From some experiments made at the hospital of St. Louis in Paris, it appears that twelve grains will cause nausea, pain in the stomach and bowels, vomiting and diarrhœa.[5] There is no doubt that the carbonate or natural verdigris, the phosphate, and even the subphosphate, though quite insoluble in water, are capable of acting as poisons, because Lefortier found that they are soon dissolved in the stomachs of dogs, and in small doses cause severe vomiting in the course of fifteen minutes.[6] But it is chiefly in the soluble salts that we are to look for the full development of the action of this poison. A very small quantity of the sulphate will prove fatal; for, as already noticed, Drouard found that six grains killed a dog in half an hour.
The symptoms caused by the soluble salts of copper in man are, in a general point of view, the same with those caused by arsenic and corrosive sublimate. But there are likewise some peculiarities. According to the cases related by Orfila in his Toxicology, the first symptom is violent headache, then vomiting and cutting pains in the bowels, and afterwards cramps in the legs and pains in the thighs. Sometimes throughout the whole course of the symptoms there is a peculiar coppery taste in the mouth, and a singular aversion to the smell of copper. Drouard notices this in his thesis; and says, that, having himself been once poisoned with verdigris, the smell of copper used to excite nausea for a long time after.[7] Another symptom, which occasionally occurs in this kind of poisoning, and never, so far as I know, in poisoning with arsenic or corrosive sublimate, is
