The organic constituents of plants and vegetable substances and their chemical analysis / by G.C. Wittstein ; authorised translation from the German original, enlarged with numerous additions, by Baron Ferd. von Mueller.

  • Wittstein, Georg Christian, 1810-1887.
Date:
1878
Catalogue details

Licence: Public Domain Mark

Credit: The organic constituents of plants and vegetable substances and their chemical analysis / by G.C. Wittstein ; authorised translation from the German original, enlarged with numerous additions, by Baron Ferd. von Mueller. Source: Wellcome Collection.

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    [Ag'aric Acid together with Ag'aric Resin have been prepared by G. Flemy from Polyporus officinalis by extracting with ether. Agaric resin is brown-red, pulverised light-brown; insoluble in water, easily soluble in ether and in absolute alcohol, less in alco- hol of 70%, also in methylic alcohol, chloroform, acetic acid, in- soluble in benzol and sulphide of carbon j easily soluble in am- monia and diluted potash-ley. It is only slightly bitter and fuses at 89-7°. Agaric Acid crystallises in fine, white needles, fuses at 145*7°, not sublimable, dissolves easily in strong alcohol, less in chloro- form, very little in ether and acetic acid, still less in sulphide of carbon and benzol. Water dissolves very little of it, but assumes an acid reaction. Its centesimal composition is C = 6344, 11 = 9-75, 0 = 26-81.] Ag'aricin, Solid, crystallisable fat, contained in mushrooms (Agaricus campestris and many other species), fusing between 148-150°, is not affected by caustic alkalies. AgTOStemmin, Alkaloid alleged to exist in the seeds of Lychnis Githago. Obtained by extracting with alcohol of 40 per cent, containing acetic acid, and by precipitating with calcined magnesia. The precipitate to be treated with alcohol and left to crystallise. Yellowish white, minute scales, fusible by heat and slowly soluble in water, of perceptibly alkaline reaction and yielding crystallisable salts with acids. [Ailantic Acid, prepared by Narajan-Dagi from the bark of Ailantus excelsa. The decoction of the bark is freed from lime by oxalic acid, from gum and colouring matter by sub- acetate of lead; the liquid is then evaporated after treating with sulphuret of hydrogen. Eeddish brown, very bitter, deliquescent mass of wax-consistence, very easily soluble in water, less in alcohol and ether, insoluble in chloroform and benzol.] Albumin. The widest distributed of the protein-substances and found in the sap of all vegetables, but occurring- also in the solid or curdled state. When these juices are heated to the boiling point or only to 75°, the albumin loses its solubility and separates in almost white flakes, frequently coloured green by chlorophyll. By treating the coagulated mass successively with alcohol, ether and water containing hydrochloric acid, the albu- min remains after drying as a yellowish or grey-white trans- parent mass, which swells up in water without dissolving in it, and by its behaviour coincides with protein {see Protein-sub- stances). In order to determine the quantity of albumin con- tained in a liquid, collect after the latter has been purified in the above manner in a weighed filter, and dry at 120°