692 URINE. 



Carbamic-acid ethylester (urethane), as shown by JAFFE/ may pass, by the 

 mutual action of alcohol and urea, into the alcoholic extract of urine when one 

 is working with large quantities. 



FOLIN 2 claims that all human urine contains a body which is probably methyl- 

 urea. 



X NH CO 



Creatinine, C4H 7 N 3 O, or NH:C<; | , is the anhydride of 



X N(CH 3 ).CH 2 



xNH 2 

 Creatine, NH:C\ , which occurs in the muscles, 



X N(CH 3 ).CH 2 .COOH 

 bird urine and sometimes also in human urine. 



Creatinine occurs in human urine and in that of certain mammalia. 

 It has also been found in ox-blood, milk, though in very small amounts, 

 in meat extracts, and in the flesh of certain fishes. 



The quantity of creatinine in human urine is, in a grown man voiding 

 a normal quantity of urine in the course of a day, 0.6-1.3 grams (NEU- 

 BAUEE), or on an average 1 gram. JOHNSON 3 found 1.7-2.1 grams per 

 day, and similar results have been obtained by v. HOOGENHUYZE and 

 VERPLOEGH. 4 The quantity of creatinine with a diet free from meat 

 is, FOLIN 5 says, variable for different individuals, but is constant for the 

 same person. He never found the quantity below 1 gram and often 

 between 1.3 and 1.7 grams. Nurslings also eliminate creatinine, although 

 the quantity is small (v. HOOGENHUYZE and VERPLOEGH). The quantity 

 of creatinine nitrogen in per cent of the total nitrogen varies under 

 different conditions, but is on an average about 4.5-6.9 per cent, as 

 determined by several experimenters. 



Creatine occurs especially in the urine of birds and also in the urine 

 of nurslings, but also in older children (ROSE, FOLIN and DENIS). It 

 has also been found in the urine of pregnant women (KRAUSE and CRAMER) 

 but otherwise only in starvation, in diabetes, diseases of the liver, fevers 

 and diseases accompanied by a destruction of the body proteins, espe- 

 cially muscle-proteins. Between creatine and creatinine elimination a 

 relation exists it seems, at least for certain cases, namely with a decrease 

 in the quantity of creatinine eliminated the quantity of creatine increases 

 (LEVENE and KRISTELLER) . 6 



1 Zeitschr. f . physiol. Chem., 14. 



2 Journ. of biol. Chem., 3. 



* Huppert-Neubauer, Harnanalyse, 10. Aufl., 387. 



4 Zeitschr. f . physiol. Chem., 46. 



6 Amer. Journ. of Physiol. 13; af. Klercker, Hofmeister's Beitrage, 8. 



6 Rose, Journ. of biol. Chem., 10; Folin and Denis, ibid., 11; Krause and Cramer, 

 Journ. of Physiol., 40 (Proc. physiol. Soc., July, 1910, LXI); Schaffer, Amer. Journ. 

 of Physiol., 23; Levene and Kristeller, ibid., 24. 



