660 URINE. 



Reports as to the behavior of the creatinine elimination with work 

 are conflicting, v. HOOGENHUYZE and VERPLOEGH, who made use of 

 a much more trustworthy method of quantitative estimation than their 

 predecessors, find that muscular activity as a rule does not cause any 

 rise in the creatinine elimination, and that in man such a rise with work 

 occurs only when the body is obliged to live upon its own tissues. 

 S. WEBER 1 also finds an absolute increase in the elimination of 

 creatinine only in starving dogs. 



In starvation a decrease in the creatinine but a simultaneous increase 

 in the elimination of creatine has been found in man (v. HOOGENHUYZE 

 and VERPLOEGH, CATHCART, BENEDICT and MYERS 2 ). Little is known 

 about the behavior of creatinine in disease nor are the observations in 

 accord. In anaemia and cachexia the elimination of creatinine is dimin- 

 ished, and when the metabolism is increased the elimination is also 

 increased. That this is the case, at least in fevers, seems to be 

 borne out by several concurrent observations. 3 In diseases of the liver 

 a diminished elimination of creatinine may occur and in cases of car- 

 cinoma of the liver considerable creatine has been found in the urine 

 (v. HOOGENHUYZE ana VERPLOEGH, MELLANBY). 



Creatinine crystallizes in colorless, shining monoclinic prisms which 

 differ from creatine crystals in not becoming white with loss of water 

 when heated to 100 C. It dissolves in 11 parts cold water, but more 

 easily in warm water. It is difficultly soluble in cold alcohol, but the 

 reports in regard to its solubility differ widely. 4 It is more soluble 

 in warm alcohol and nearly insoluble in ether. In alkaline solution 

 cieatinine is very easily converted into creatine on warming. 



Creatinine gives an easily soluble crystalline compound with hydro- 

 chloric acid. A solution of creatinine acidified with mineral acids gives 

 crystalline precipitates with phosphotungstic and phosphomolybdic 

 acids even in very dilute solutions (1:10000) (KERNER, HOFMEISTER 5 ) . 

 It is precipitated, like urea, by mercuric-nitrate solution and also by 

 mercuric chloride. On treating a dilute creatinine solution with sodium 

 acetate and then with mercuric chloride a precipitate of glassy globules 

 having the composition 4(C4H 7 N 3 O.HCl.HgO)3HgCl2 separates on stand- 

 ing some time (JOHNSON). Among the compounds of creatinine, that 



1 Arch. f. exp. Path. u. Pharm., 58. Further literature may be found in v. Hoog- 

 enhuyze and Verploegh, Zeitschr. f. physiol. Chem., 46. 



2 v. Hoogenhuyze and Verploegh, Zeitschr. f. physiol. Chem., 57; Cathcart, Bioch. 

 Zeitschr., 6; Benedict and Myers, Amer. Journ. of Physiol., 18; Jaffe, 1. c. 



3 See O. v. Klercker, Zeitschr. f. klin. Med., 68. 



4 See Huppert-Neubauer, 10. AufL, and Hoppe-Seyler-Thierfelder's Handbuch* 

 8. Aufl. 



5 Kerner, Pfliiger's Arch., 2; Hofmeister, Zeitschr. f. physiol. Chem., 5. 



