Arsenic

Arsenic (As = 75). An element known from the earliest times. Sometimes found native, but usually as sulphide in combination with sulphide of iron. Prepared from the ore by heating the latter in earthen vessels, the metallic arsenic sublimes, and is condensed in a suitable receiver. It is a steel-grey brittle metal, which volatilises at a dull red heat without melting, and gives off an odour of garlic: it oxidises slowly in the air at ordinary temperatures, and rapidly if heated, into arsenious oxide. Arsenic is on the border line between the metals and non-metals, resembling the former in physical properties, and the latter in its chemical relations. Compounds of arsenic are used in medicine, and the metal itself in the manufacture of leaden shot, and the preparation of alloys generally.

The symptoms of arsenical poisoning are epigastric pain and tenderness, vomiting and diarrhoea; collapse rapidly develops and death may occur in a few hours, if a large quantity of poison has been consumed, or in less acute cases life may be prolonged for some days, and cramps, tremors, or even convulsions may then appear, and if recovery should take place these nervous phenomena may persist for some time. Arsenic has been at times administered in small, repeated doses to avoid suspicion rather than in one large dose; in such cases vomiting and wasting with coryza and irritation of the conjunctivae have been the most prominent symptoms.

The congested state of the mucous membrane of the digestive tract after death, and the application of Marsh's and Reinsch's test to the contents of the stomach, usually leave no doubt in suspected cases of arsenic poisoning. Emerald green, or aceto-arsenite of copper, has given rise to unpleasant symptoms, from its use in confectionery, in painting children's toys, and particularly in connection with wall papers. So much attention has been directed to this subject that such cases of chronic poisoning are now fortunately becoming rare.