Note 413 — PHARMACOLOGIA. (continued 2)

This opinion has lately received ample confirmation from the experiments of Dr. Christison, (Edinb. Med. and Surg. Journal, July, 1824) who has shewn that the process of Orfila is objectionable on the three following grounds, viz.

1st. The colour is very seldom so entirely destroyed but that the precipitates produced by some of the tests still deviate to a certain degree from their characteristic tints; and although the colour of the fluid be even destroyed entirely, it often re-appears in the precipitates.

2d. Although the Chlorine destroys the colour, it does not also take from the fluid its solvent action on the arsenical precipitates.

3d. In fluids decolorized by Chlorine, and containing no Arsenic, some of the tests produce precipitates, not only precisely the same with those which they cause in the decolorized solutions of Arsenic, but likewise very similar in appearance to those caused in a pure aqueous solution of Arsenic.