448 ACETONE BODIES 



whether the diacetic acid arising in metabolism is to be 

 excreted unchanged or as acetone. According to Liithje 43 

 a portion of the diacetic acid may perhaps be excreted by 

 the kidneys as an alkaline salt, provided sufficient supply of 

 alkali be available; this portion otherwise appearing as 

 acetone. 



Determination of Acetone and Diacetic Acid. In con- 

 clusion a few remarks upon the quantitative determination 

 of the acetone bodies are desirable. 44 



In the determination of acetone, precedence is still given 

 to the long approved Messinger-Huppert method. This con- 

 sists in distillation of the acetone from the urine, transform- 

 ing it into iodoform by means of iodide of potassium in an 

 alkaline solution, and determining by titration the amount 

 of iodine used in the formation of iodoform. Acetone can 

 also be separated from the distillate by nitrophynylhy- 

 drazine (according to Eckenstein and Blancksma) as a bright 

 yellow crystalline sediment, and weighed. 45 It may, too, be 

 precipitated by an alkaline solution of mercuric cyanide, the 

 acetone-mercurial precipitate broken up by acids, and the 

 mercury determined by titration (very like Vollhard's method 

 of determining silver). 46 Finally the fixation of sodium 

 bisulphite by acetone may be used for iodometric estimation, 

 provided a very long period of reaction is given ; 47 while in 

 experiments of short duration hydrolytic dissociation is so 

 marked that besides the fixed sulphurous acid there is always 

 present a considerable fraction in free state. 48 In the de- 



43 H. J. Ltithje (Kiel), Therap. d. Gegenw., 51, 8, 1910. 



44 Literature upon the Quantitative Determination of the Acetone Bodies : 

 G. Embden and G. Schmitz, Handb. d. Biochem., 3, 906-939, 1910; E. Letsche, 

 ibid., 5, 1, 197-199, 1911; cf. also G. Embden and L. Michaud, Biochem. 

 Zeitschr., 13, 262, 1908; Hofmeister's Beitr., 11, 332, 1908. 



45 S. Holler (v. Leyden's Clinic), Zeitschr. f. klin. Med., 64, 207, 1907; 

 W. C. de Graaff, Pharmac. Weekbl., 44, 555; Jahresber. f. Tierchem., 37, 356, 

 1907. 



48 H. Scott Wilson (Oxford), Jour, of Physiol., 42, 444, 1911. 

 47 A. Jolles, Ber. d. deutsch. chem. Ges., 39, 1306, 1906. 

 *J. Mondschein (under direction of O. v. Fiirth), Biochem. Zeitschr., 

 42, 95-97, 1912. 



