Chemistry of urine : a practical guide to the analytical examination of diabetic, albuminous and gouty urine.

  • Alfred Henry Allen
Date:
1895
Catalogue details

Licence: Public Domain Mark

Credit: Chemistry of urine : a practical guide to the analytical examination of diabetic, albuminous and gouty urine. Source: Wellcome Collection.

Provider: This material has been provided by the Gerstein Science Information Centre at the University of Toronto, through the Medical Heritage Library. The original may be consulted at the Gerstein Science Information Centre, University of Toronto.

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    chloric acid or dilute sulphuric acid, with formation of euxanthone and an acid which has been shown by Spiegel {Ber., xv. 1965) to be identical with gly- curonic acid, CigHigOji = CigHgO^ + CgH^QO;. In fact purree is the best material for the preparation of glycuronic acid, which can be obtained on the small scale by the following process :—The artists' water- colour known as Indian yellow is ground up with sand, and then treated with dilute hydrochloric acid, which dissolves out calcium and magnesium salts, &c. The residue is washed with water and treated with a solution of ammonium carbonate, which dissolves the euxanthic acid, leaving euxanthone and sand undis- solved. From the filtered liquid the euxanthic acid is precipitated by dilute hydrochloric acid, washed with cold water, and then heated with water in a closed soda-water bottle to 125° C. for three or four hours. The requisite temperature can be conveniently obtained by immersing the bottle in a bath of molten paraffin wax (candles). From the cooled product the euxanthone is dissolved by agitation with ether, and the glycuronic anhydride crystallised from the concen- trated aqueous liquid. Glycuronic acid is a syrupy liquid, miscible with water or alcohol. When the aqueous solution is boiled, eva- porated, or even allowed to stand at the ordinary temperature, the acid loses the elements of water and yields the anhydride or lactone. Glycuronic Anhydride, CgHgOg, forms monoclinic tables or needles, having a sweet taste, and melting at about 160° when heat is gradually applied, or at 170-180° when heated rapidly. The anhydride is in- soluble in alcohol, but dissolves readily in water to form a dextro-rotatory solution. [«!)] = 19*25°. The solu- tion prevents the precipitation of cupric solutions by alkalies, and powerfully reduces hot Fehling's solution.