MISCELLANEOUS TESTS.—With bisul phite of soda, acetone, as well as the alde hydes, combines to a crystallic compound in thin flakes resembling much those of cholesterin, even by microscopical exam ination. (Limpricht.) Acetone in an alkaline solution com bines with iodine to form iodoform.
Freshly precipitated oxide of mercury is dissolved by acetone. Indigo is formed when acetone is combined with orthoni trobenzaldehyde in an alkaline solution. (Baeyer and Drewsen.) Bichloride of mercury recommended as a reagent for acetone and albumin, as well as for the estimation of the quan tity of glucose and nitrogen present in the urine. T'ittarelli (GP Incurabili Gior. di Clin. e di Terapia, Nos. 16 and 17, '94).
Certain substances (sugars) yield the reactions usually characterizing acetone. This is due to decomposition of sugar and formation of acetaldehyde. In test ing by the ordinary method, the urine should, therefore, be moderately acidified and distilled slowly and not too long. Salkowski (Jour. de Med., de Chir., et de Pharm., Bruxelles, Jan. 26, '95).
From what has just been stated it will become apparent. that none of the tests
are specific for acetone alone. To be quite sure that acetone is contained in the distillate, it is, therefore, necessary to try successively by all the tests, and only when all tests give positive result is the presence of acetone proved.
Von Jaksch has tried to employ the nitrocyanide test for a quantitative esti mation of the acetone, and the iodoform test has been recommended by Messinger and lluppert for the same purpose. The quantity of iodine used to form iodoform with the acetone is measured, and the quantity of the acetone present in the solution calculated by it also; but, al though Engel and Devoto are of the opinion that it is possible to make pretty accurate estimations in this way, meth ods for quantitative estimation of the acetone are not to be relied upon, as it is impossible to avoid errors caused by the presence of substances which are in fluenced by the tests in the same way as the acetone.
Diacetic acid (C = CII,—CO