CARBOHYDRATES AND REDUCING SUBSTANCES. 711 



(I'lycerophosphoric acid occurs as traces in the urine, 1 and it is probably a 

 decomposition product of lecithin. The occurrence of succinic acid in normal 

 urine is a subject of discussion. 



Carbohydrates and Reducing Substances in the Urine. The occurrence 

 of dextrose, as traces, in normal urine is highly probable, as the investiga- 

 tions of BRU CKE, ABELES, and v. UDRANSZKY show. The last investigator 

 has also shown the habitual occurrence of carbohydrates in the urine, and 

 their presence has been positively proven by the investigations of BAU- 

 MANN and WEDENSKI, and especially by BAISCH. Besides dextrose normal 

 urine contains, according to BAISCH, another not well-studied variety 

 of sugar; according to LEMAIRE, probably isomaltose is present, and 

 besides this a dextrin-like carbodydrate (animal gum), as shown by 

 LANDWEHR, WEDENSKI, and BAISCH. The quantity of carbohydrates, 

 eliminated under normal conditions in the twenty -four hours' urine and 

 determined by the benzoylation method, which is perhaps not sufficiently 

 trustworthy, varies considerably between 1.5 and 5.09 giams. 2 



The precipitate obtained from concentrated urine by the aid of alcohol and 

 whose nitrogen (colloidal nitrogen according to SALKOWSKI) in normal urine 

 amounts to 2.34-4.08 per cent of the total nitrogen and in pathological urines to> 

 8-9 per cent, and in a case of acute yellow atrophy of the liver to 21.8 per cent, 

 contains, SALKOWSKI 3 claims, a nitrogenous carbohydrate which has strong reduc- 

 ing action upon alkaline copper solutions after cleavage with hydrochloric acid. 



Besides traces of sugar and the reducing substances previously men- 

 tioned, uric acid and creatinine, the urine contains still other bodies of this 

 character. These latter are partly conjugated compounds of glucuronic 

 acid, C 6 H 10 O 7 , which is closely allied to dextrose. The reducing power of 

 normal urine corresponds, according to various investigators, to 1.5-5.96 

 p. m. dextrose. That portion of the reduction belonging to dextrose 

 alone is equal to 0.1-0.6 p. m. LAVESON 4 believes that of the total 

 reduction 17.8 per cent is due to sugar, 26.3 per cent to creatinine, 7.8 

 per cent to uric acid, and the remainder, nearly 50 per cent, is caused 

 by chiefly unknown bodies. 



Chem. CentralbL, 1869; Underbill, Journ. of biol. Chem., 2; Zweifel, Arch. f. Gynakol, 

 76; Araki, Zeitschr. f. physiol. Chem., 15, 16, 17, 19. See also Irisawa, ibid., 17; 

 v. Terray, Pfliiger's Arch., 65; Schutz, Zeitschr. f. physiol. Chem., 19; Inouye and 

 Saiki, ibid., 37; Minkowski, Arch. f. exp. Path. u. Pharm., 21 and 31. 



1 See Pasqualis, Maly's Jahresber., 24. 



2 Lemaire, Zeitschr. f. physiol. Chem., 21; Baisch, ibid., 18, 19, and 20. In these 

 as well as in Treupel, ibid., 16, the works of other investigators are cited. See also 

 v. Alfthan, Deutsch. med. Wochenschr., 26. 



3 Berlin, klin. Wochenschr., 1905. 



4 Fluckiger, Zeitschr. f. physiol. Chem., 9; Laveson, Bioch. Zeitschr., 4; see also 

 Huppert-Neubauer, page 72. 



