CREATINE. 575 



the possibility that in the muscles, which according to KOSSEL and DAKIN 

 contain only little arginase, the arginine was decomposed in other ways. 

 In autolysis as well as perfusion experiments with livers, INOUYE l has 

 recently shown that an increase in the creatine occurs at the expense of 

 the arginine added. 



Starting with the observation of Jaff6 2 that glycocyamine (guanidine acetic 

 acid) in rabbits is transformed with a methylation into creatine, we can consider 

 the cleavage of arginine into creatine in the following manner, basing this con- 

 ception upon the ruling conception on the cleavage of ammo-acids and fatty acids 

 in the animal body. 



The opinions are not unanimous in regard to the organ producing 

 creatine or creatinine. Based upon several investigations it is generally 

 admitted that the liver here plays an important r61e. Several other 

 organs may also be considered and in the first place, the muscles. Accord- 

 ing to MELLANBY the creatinine is probably formed in the liver, trans- 

 formed into creatine in the muscles and there stored up as such. Other 

 observations still speak for the fact that the creatine is formed in the 

 muscles and transformed into creatinine in the liver, while according 

 to NOEL-PATON and MACKIE the exclusion of the liver in birds is without 

 effect upon the creatinine metabolism. 



Creatine crystallizes in hard, colorless, monoclinic prisms which 

 lose their water of crystallization at 100 C. It is soluble in 74 parts 

 of water at the ordinary temperature, and in 9419 parts absolute alcohol. 

 It dissolves more easily with the aid of heat. Its watery solution has 

 a neutral reaction. Creatine is not dissolved by ether. If a creatine 

 solution is boiled with precipitated mercuric oxide, this is reduced, 

 especially in the presence of alkali, to mercury and oxalic acid, and the 

 foul-smelling methyluramine (methylguanidine) is developed. A solu- 



1 Kossel and Dakin, Zeitschr. f. physiol. Chem., 41 and 42; Inouye, ibid., 81. 



2 Zeitschr. f. physiol. Chem., 48; see also Dorner, ibid., 52. 



