least soluble portion (which contains the greater part of the colouring matter) with hot ether; dissolving the remainder in alcohol; precipitating the alcoholic solution with lead acetate; decomposing the washed precipitate with sulphuretted hydrogen; extracting the colouring matter therefrom by hot alcohol; and precipitating the alcoholic solution with water.
BIX′INE (-ĭn). The yellow colouring-principle of annotta.
Prep. A solution of annotta is precipitated with a solution of acetate of lead; the precipitate, after having been washed in cold water, is decomposed by sulphuretted hydrogen; the decanted liquor or filtrate yields crystals by cautious evaporation.
Prop., &c. Yellowish white, turning full yellow by exposure to air; soluble in water, and freely so in alcohol and in alkaline solutions; by oxidation it is converted into bixeine. For a correct knowledge of both of these substances we are indebted to M. Preisser.
BLACK. Syn. A′ter,[189] Ni′ger, L.; Noir, Fr.; Schwarz, Ger.; Blac, Blæc, Sax. In dyeing, &c., of the colour of lamp-soot, or of night; subst., a black colour.
[189] Black, deep black; as opposed to albus, white.
Black Ash. The waste lye of the soapmakers is evaporated in large iron boilers, the salt separated as it falls down, and then heated in a reverberatory furnace, until it is partially decomposed and fused, when it is run into iron pots to cool. It is used in the manufacture of alum and common soap.
Black Col′ours (kŭl′-). See Black Pigments.
Black Draught. See Mixture, Senna (Compound).
Black Drop. See Drops, Patent Medicines, &c.