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Characteristics. —Copper is easily recognized by its colour, by itscommunicating a green tinge to flame, and by dissolving it in nitric acid.The solution possesses the following properties: it is blue, or greenishblue; potash or soda occasions a blue precipitate of the hydratedoxide of copper; a small quantity of ammonia produces a similar bluishwhite precipitate, but an excess redissolves it, forming a deep blueliquid : ferrocyanide of potassium occasions a reddish brown precipitateof the ferrocyanide of copper; the hydrosulphurets throw down theblack sulphuret; and, lastly, a polished iron plate plunged into theliquid, becomes coated with metallic copper.
Physiological Effects. — (a.) Of metallic copper —Metallic copperappears to produce no pernicious effects when taken internally, so longas it retains its metallic state, as many cases are recorded where coinsof this metal have been swallowed and retained for a considerabletime without any ill effects arising ; and Drouard ( Exper. et Observ. surVEmpoisonnem. par VOxide de Cuivre, Paris, 1802) gave as much as anounce of finely powdered copper to dogs of different ages and sizes, butnone of them experienced any inconvenience.
Notwithstanding these facts, however, various effects have been attri-buted to it. Thus, Cothenius (Voigtel, Arzneimittellehre) says, copperfilings operate by stool, urine, and saliva; and the late Professor Barton(Chapman’s Elem. of Therap. ii. 457) was accustomed to relate auinstance of a child, who, having swallowed a cent, continued for sometime to discharge several pints of saliva. Lastly, Portal (Orfila, Toxicol.Gen.) mentions a case in which copper filings, incorporated with crumbof bread, acted powerfully on the system. I have no doubt but that theeffects here mentioned arose from the oxidation of the metal by the acidsof the alimentary canal.
(, b.) Of the Cupreous Compounds. —If the cupreous preparations beused in very small doses, they sometimes give relief in certain diseases(principally of the nervous system), without obviously disordering thefunctions ; in other words, in these instances the only apparent effect isthe modification observed in the morbid condition. These are the casesin which these preparations have been termed tonic, antispasmodic, oralterative, according to the nature of the disease; thus, in ague theyhave been termed tonic, in epilepsy antispasmodic, in dropsy alterative.The beneficial operation is presumed to be owing to some influenceexerted by the remedy over the nervous system. The effects producedby the long-continued use of small doses of the preparations of copperhave not been satisfactorily determined; they are said to be variousaffections of the nervous system (such as cramps or paralysis), alterationof the colour of the skin, chronic inflammation of the respiratory anddigestive apparatus, slow fever, and wasting of the body. Thesesymptoms constitute what has been termed slow, or chronic poisoning bycopper. The smelters and workers in copper do not suffer from thevapour or emanation of this metal, as the workmen employed in thepreparation of mercury, of arsenic, or of lead do, from the vapours ofthese metals ; this, indeed, might be expected, when we consider howmuch more volatile the latter and their preparations are, than copper andits compounds. In larger, or full medicinal doses, these remedies actas emetics, exciting speedy vomiting, with less nausea than tartar emeticproduces. In still larger quantities these bodies act as poisons, giving