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 same taste with these four, and therefore will certainly be found to contain the acid also. The same inference may be drawn from the taste of some pomaceous seeds; and accordingly I have obtained a hydrocyanated oil from the seeds of the New York pippin, and those of the white-beam-tree, the Pyrus aria. The poison procured from these sources exists in two forms,—as a distilled water, and as an essential oil. Further, the acid has been discovered to constitute the active poison of the juice of the Janipha manihot, or bitter cassava [see p. 457]. The distilled waters yield hydrocyanic acid, as is shown by the blue precipitate they give with potass and the mixed sulphates of iron. They have a powerful, peculiar, grateful odour, which is usually likened to that of pure hydrocyanic acid. But the smell really bears very little resemblance to that of hydrocyanic acid, and is not owing to its presence: the odour remains equally strong after the acid is thrown down by the test now mentioned. The active part of the distilled water may be separated in the form of a volatile oil. This is colourless at first, afterwards yellowish or reddish, acrid, bitter, heavier than water, and very volatile. The essential oil of the bitter almond has been carefully examined by various chemists. Vogel, by subjecting it twice to distillation from caustic potass, procured hydrocyanate of potass in the residue; and a volatile oil was distilled over, which no longer contained hydrocyanic acid, but nevertheless had the odour of the original oil. This purified oil he considered equally poisonous with that which contains hydrocyanic acid, a single drop of it having killed a sparrow; and his opinion was confirmed by the experiments of Professor Orfila. But according to some careful experiments by Stange, which have been amply confirmed by Dr. Göppert of Breslau, and also by MM. Robiquet and Boutron-Charlard, —if the purified oil retains active poisonous properties, this must be owing to the acid not having been entirely removed. Göpmert in particular remarked that twenty-five drops of the purified bitter-almond oil, cherry-laurel oil, or bird-cherry oil had very little effect on rabbits, not more indeed than the same quantity of the common essential oils. The purified oil, according to all these chemists, possesses the odour of the original oil, as Vogel first stated. Of the Bitter Almond.

The bitter almond was once extensively used in medicine, and is still much employed by confectioners for flavouring puddings, sweatmeats, and liqueurs. It is the kernel of the fruit of the ''Amygdalus communis''. This species has too varieties, the dulcis and the amara; which differ from one another in the fruit only. The fruit of the former yields the sweet, and of the latter the bitter almond. The bitter almond is the smaller of the two. The two plants, according