Handbook for the bio-chemical laboratory : including methods of preparation and numerous tests arranged alpabetically / by John A. Mandel.

Date:: 1896

Credit: Handbook for the bio-chemical laboratory : including methods of preparation and numerous tests arranged alpabetically / by John A. Mandel. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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$rapidly deliquesce in the air. It is readily soluble in water and alcohol, yielding a solution with a bitter-sweetish taste. Its salts are, as a rule, readily soluble in water, and the solu- tions of the alkali salts are not precipitated by copper sulphate, silver nitrate, or sugar of lead, but are precipitated, on the contrary, by basic lead acetate. The aqueous solution of the alkali salts foam like soap. On boiling with acids and alkalies it splits into cholalic acid and taurin. Both aqueous and alco- holic solutions of taurocholic acid are dextro-rotatory. Spe- cific rotation of its alcoholic solution is (a) Z> = -f 25°. Cholalic Acid, C„H„0,. Preparation.—1. 500 c.c. bile are treated with 75 grms. barium hydrate and the mixture boiled for 24 hours on the sand-bath. The flask should be connected with a return con- denser. Allow the liquid to cool, and filter. Add concen- trated hydrochloric acid to the filtrate, which decomposes the barium cholalate, depositing impure cholalic acid. These crystals are separated fi-om the mother-liquor and pressed, and dissolved in a solution of caustic soda; the solution is then mixed with 30 grms. animal charcoal and allowed to stand for a few days. It is next filtered and the filtrate decomposed with hydrochloric acid, filtered again and washed thoroughly and the substance from the filter dissolved by the smallest possible quantity of hot alcohol. The alcoholic solution is treated with water until a slight turbidity appears. On the liquid being cooled cholalic acid separates in the form of hard, transparent tetrahedra or in clumps of radiating needles. For further purification recrystalli/e from methyl alcohol. {Mylius.) 2. Mix ox-bile with one fifth of its weight of a 30^ caustic- soda solution and boil for 24 hours on water-bath, having the flask connected with a return condenser. Now saturate the liquid with CO, and evaporate, to dryness. Extract the residue with strong alcohol, which dissolves the sodium salts$