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.

  • Georg Christian Wittstein
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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    and an odour of burnt sugar; dissolves little in cold, readily in boiling water, the light-yellow solutions becoming colourless with acids; little soluble in cold, more so in hot alcohol, not in ether, readily in alkalies with gold-yellow colour; the ammoniacal solu- tion becomes bro^vn by keeping, but not the solutions of the fixed alkalies; breaks up with diluted acids into sugar and quercetin. RoceelliC Aci(l=C34 H30 Oc + 2 HO. In Roccella fuciformis and in Lecanora tartarea. Treat with water and ammonia, preci- pitate the filtrate with chloride of calcium, decompose the deposit with hydrochloric acid and purify the crystals that have formed by dissolving in ether.—Forms delicate, white, silvery, quadrangu- lar, tabular crystals, obtained in short needles from alcohol, inodorous and tasteless, of acid reaction in the alcoholic solution; fuses at 130° without loss of weight, evaporates partly below 200°, and is partly converted into the anhydrous acid and decomposed by a higher temperature; is quite insoluble in water, dissolves in 18 parts alcohol of 0'819, readily in ether; forms with alkalies half- acid soluble, with the other bases mostly insoluble salts. Roccellillill=C36 H16 O14. In Roccella tinctoria. Treat with water containing lime, filter, precipitate the filtrate with hydro- chloric acid and boil the deposit, consisting of Roccellinin and lecanoric acid (named formerly /Sorsellic acid), repeatedly Avith water, leaving the R. undissolved, which has to be recrystallised in alcohol.—Fine, hair-shaped crystals of silky gloss, insoluble in water, slightly soluble in cold alcohol and in ether, a little more when hot, readily in alkalies and in alkaline earths ; assumes a permanent green-yellow colour with solutions of chloride of lime. Rottlerill (Kamalin) = C.22 Hio Oq. In the kamala, the stellated hairs and glandules that cover the fruit of Mallotus Philipinensis. It crystallises from the ethereous tincture in yellow needles of a silky gloss, fuses by heat and becomes decomposed in higher temperatures; is insoluble in water; dissolves in alkalies with deep-red colour, little in cold, more in boiling alcohol, and readily in ether. Riiberytliric Aci(l=C72 H40 O40 or C50 H31 O31. In the root of R,ubia tinctorum, according to Rochleder; Schunck believes the above acid to be a product of decomposition of rubian, and perha] s identical with a substance named by him rubianic acid. Precipitate with acetate of lead the aqueous decoction of madder, remove the deposit (which may be used for the preparation of alizarin and purpuiin), and precipitate the filtrate with subacetate of lead, but not in excess, producing a dark flesh-coloured nnd almost briclc-red deposit, which contains R.ul)erythric, rubichloric, a little citric and phosphoric acids. Decompose the deposit under water with sul- phuret of hydrogen; separate the liquid, containing mostly rubi- o