548 MUSCLES. 



are also included. According to MELLANBY the creatinine is probably 

 formed in the liver and transformed into creatine in the muscles and there 

 deposited as such. 



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- 

 tion of creatine in water is not precipitated by basic lead acetate, but 

 gives a white, flaky precipitate with mercurous nitrate if the aci v d reac- 

 tion is neutralized. When boiled for an hour with dilute hydrochloric 

 acid, creatine is converted into creatinine, and may be identified by its 

 reactions. On boiling with formaldehyde it can be transformed into' 

 dioxymethylenecreatinine, which crystallizes readily (JAFFE 1 ). 



The preparation and detection of creatine is best accomplished by the 

 following method of NEUBAUER, 2 which was first used in the preparation 

 of creatine from muscles : Finely cut meat is extracted with an equal weight 

 of water at 50-55 C. for 10-15 minutes, pressed, and extracted again 

 with water. The proteins are removed from the united extracts so far 

 as possible by coagulation at boiling heat, the filtrate precipitated by the 

 careful addition of basic lead acetate, the lead removed from this filtrate 

 by H 2 S, and the solution then carefully concentrated to a small volume. 

 The creatine, which crystallizes in a few days, is collected on a filter, 

 washed with alcohol of 88 per cent, and purified, when necessary, by 

 recrystallization. The quantitative estimation of creatine is performed 

 by transforming it into creatinine (see Chapter XV) . 



Carnine, C7H 8 N 4 O3 + H 2 O, is one of the substances found by WEIDEL 

 in American meat extract. It has also been found by KRUKENBERG 

 and WAGNER in frog muscles and in the flesh of fishes, and by POUCHET 

 In the urine. Carnine, which may be transformed into hypoxanthine 

 by oxidation is, according to HAISER and WENZEL, 3 probably only an 

 equimolecular mixture of hypoxanthine and a pentoside, CioH^NjO-, 

 called inosine, which is crystalline, and which readily splits' into 

 hypoxanthine and pentose by the action of acid. 



Carnine has been obtained as a white crystalline mass. It dissolves 



1 Ber. d. d. Chem. Gesellsch., 35. 



3 Zeitschr. f. analyt. Chem., 2 and 6. 



3 Weidel, Annal. d. Chem. u. Pharm., 158; Krukenberg and Wagner, Sitznngsber. 

 d. Wiirzb. phys.-med. Gesellsch., 1883; Pouchet, cited from Neubauer-Huppert, 

 Analyse des Harnes, 10. Aufl., 335; Haiser and Wenzel, Monatsch. f. Chem., 29. 



