Читать книгу Legal Chemistry - Alfred Naquet - Страница 12

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This method is exceedingly simple: Aqua regia (a mixture of two parts of hydrochloric and one part of nitric acids) is placed in a tubular retort provided with a receiver, and the organic materials, which have previously been cut into small pieces, added; the reaction commences immediately; if it is not sufficiently active, it is accelerated by a gentle heat: lively effervescence now occurs, and the destruction of all non-oleaginous substances is soon accomplished. The latter substances alone are not immediately decomposed by aqua regia, which attacks them only after prolonged action. As soon as the operation is concluded, the apparatus is removed from the fire and taken apart. The fluid condensed in the receiver is added to that remaining in the retort, and the whole thoroughly cooled in an open dish. The fatty matters now form a solid crust upon the surface of the fluid, which is removed and washed with distilled water, and, the washings being added to the rest of the solution, the latter is directly examined for metallic poisons. It is recommended by Gaultier de Claubry, in cases where the detection of arsenic is desired, to saturate and afterwards boil the suspected fluid with sulphuric acid, in order to remove the nitric and hydrochloric acids present.