698 URINE. 



The same method is used in the determination of creatine, which 

 for this purpose is first converted into creatinine by wanning with dilute 

 mineral acid. The quantity of creatine is the difference obtained between 

 the values for creatinine before and after treatment with acid. More 

 detailed directions can be found in the cited works of FOLIN, v. HOOGEN- 

 HUYZE and VEKPLOEGH, GOTTLIEB and STANGASSINGER. 



In regard to other methods, see the works of KOLISCH and 



Xanthocreatinine, CsHio^O. This body, which was first prepared from 

 meat extract by GAUTIER, has been found, by MONARI, in dog's urine after the 

 injection of creatinine into the abdominal cavity, and in human urine after several 

 hours of exhaustive marching. According to COLASANTI it occurs to a relatively 

 greater extent in lion's urine. STADTHAGEN 2 considers the xanthocreatinine 

 isolated from human urine after strenuous muscular activity as impure creatinine. 



Xanthocreatinine forms thin sulphur-yellow plates, similar to cholesterin, 

 which have a bitter taste. It dissolves in cold water and in alcohol, and gives 

 a crystalline compound with hydrochloric acid and a double compound with 

 gold and platinum chloride. It gives a compound with zinc chloride, which 

 ^crystallizes in fine needles. Xanthocreatinine has a poisonous action. 



Methylguanidine occurs, according to ACHELIS, KUTSCHER and LOHMANN, 

 to a slight extent as a regular constituent of the urine of man, horse and dog. 

 It has been found in urines associated with dimethylguanidine by ENGELAND.* 



HN CO 



I i 

 Uric Acid, Ur, C5H 4 N 4 3 ; 2, 6, 8-trioxypurine, OC C NH V , has 



I II >CO 



vr n ISJTT/ 



HN C 



been prepared synthetically by HORBACZEWSKI by fusing urea anu 

 glycocoll, or by heating trichlorlactic-acid amide with an excess of urea. 

 BEHREND and ROOSEN prepared it from isodialuric acid and urea; it 

 is also readily produced from isouric acid on boiling with hydrochloric 

 acid (E. FISCHER and TULLNER) and finally E. FISCHER and ACH 4 have 

 prepared uric acid from pseudouric acid by heating with oxalic acid to 

 145 C. 



On strongly heating uric acid it decomposes with the formation of 

 urea, hydrocyanic acid, cyanuric acid, and ammonia. On heating with 

 concentrated hydrochloric acid in sealed tubes to 170 C. it splits into 

 glycocoll, carbon dioxide, and ammonia. By the action of oxidizing 

 agents splitting and oxidation take place, and either monoureides or 

 diureides are produced. By oxidation with lead peroxide, carbon dioxide, 



i J Kolisch, Centralbl. f. innere Med., 1895; Gregor, Zeitschr. f. physiol. Chem., 31. 



2 Gautier, Bull, de 1'acad. de m6d. (2), 15, and Bull, de la soc. chim. (2), 48; Monari, 

 Maly's Jahresber., 17; Colasanti, Arch. ital. d. Biologie, 15, Fasc. 3; Stadthagen, 

 Zeitschr. f . klin. Med., 15. 



3 Achelis, Centralbl. f . Physiol., 20, 455, and Zeitschr. f. physiol. Chem., 50; Kut- 

 r scher and Lohmann, ibid., 49; Engeland, ibid., 57. 



4 Horbaczewski, Monatshefte f. Chem., 6 and 8; Behrend and Roosen, Ber. d. d. 

 chem. Gesellsch., 21; Fischer and Tiillner, ibid., 35; Fischer and Ach, ibid., 28. 



