136 BASIC BODIES. 



then removed by boiling, from the fluid which is thus obtained, and 

 the phosphates by caustic baryta; during the evaporation of the 

 fluid filtered from these precipitates the surface will be continually 

 covered with a membranous coating which must from time to time 

 be removed ; after the fluid has been evaporated to -^th of 

 its volume it must be left to stand for some time, when the creatine 

 will separate in needles. The crystals, when separated from the 

 mother-liquid by filtering paper, must be washed with water and 

 spirit of wine, and then again suffered to crystallise from hot 

 water. 



The following method is likewise given by Liebig for obtaining 

 creatine from urine. The urine, after being treated with lime-water 

 and chloride of calcium, and being filtered, is evaporated, and the 

 greater part of the salts removed by crystallisation ; the mother- 

 liquid poured off from the crystals is then decomposed with -^-th 

 of its weight of a syrupy solution of chloride of zinc ; after some 

 days, roundish granules of a compound of chloride of zinc and 

 creatinine, with which some creatine is mixed, become separated ; 

 these granules, after being dissolved in boiling water, are treated 

 with hydrated oxide of lead until there is an alkaline reaction. 

 The fluid, after the removal of the oxide of zinc and chloride of 

 lead by filtration, is freed from the lead and colouring matter by 

 means of animal charcoal, and evaporated to dryness. The residue, 

 consisting of creatine and creatinine, is treated with boiling alcohol, 

 in which the latter dissolves readily, while the former is almost 

 insoluble in it ; by this means the two bodies can therefore be 

 easily separated. 



Tests. In order to examine whether creatine be present in a 

 fluid, (for which purpose a large amount of material is required,) 

 one of the above methods should be adopted, and the properties 

 of any creatine-like substance compared with those of pure 

 creatine. As, however, the determination of the atomic weight 

 is not so readily made as in the acids, an elementary analysis is 

 indispensable for the attainment of perfect certainty. 



Physiological Relations. 



Occurrence. Chevreul long since drew attention to this sub- 

 stance as a constituent of the decoction of flesh, but its presence 

 was not again detected by any of the analysts who sought for 

 it, until Schlossberger* found it in the muscular tissue of an 



* Ann. d. Ch. u. Pharm. Bd. 49, S. 341, 



