Publisher's Synopsis
This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1824 edition. Excerpt: ... NOTES TO THE SECOND VOLUME. Note CC. p. 5. Mr Braconnot published in the Annales de Chimie, vol. Ixxxiv. a chemical examination of the husks of walnuts. The juice of the husks, examined by reagents, exhibited the following effects: It strongly reddened infusion of litmus. Solution of gelatin formed in it a slight precipitate, which he ascribed to tannin. Sulphate of iron gave the juice so deep a green, that it appeared black. No precipitation took place, even on standing some time, in consequence of the free acid found in the mixture, which is capable of imparting a fine grey to wool or silk. Oxalate of ammonia indicated the presence of lime. Nitrate of barytes produced no signs of any sulphate. Nitrate of silver acts on it in a manner well adapted to reveal the presence of the alterable hydrocarburet radical, for it produces a pretty copious precipitate, which quickly becomes coloured, while the silver resumes its metallic lustre from the action of the vegetable substance on the oxygen of the oxide. The precipitate is then no longer soluble, but in part, in nitric acid, and leaves charcoal as a residuum. Alkalies change the juice to a deep red, and form in it precipitates that contain lime. Acetate of lead occasioned in the juice a whitish, flocculent, very copious precipitate, which dissolved entirely in distilled vinegar. From this precipitate, malic and citric acids were obtained. Subacetate of lead produced a new precipitate with the preceding liquid, and rendered the whole nearly colourless. This sediment yielded malic acid, colouring matter, and tannin. The magma left after expression of the juice, after having been treated with alcohol, which extracted from it some green resinous matter, was heated with water till it boiled, to...
