XANTHO-CREATININ. 457 



methyl guanidin, etc. Almost all of these are poisonous. They 

 are less abundant than the others. 



(a) Xanthin bases. Exist in minute amount in meat and are not 

 toxic. 



(b) Carbopyridic bases. Likewise present only in small amount. 

 They produce stupefaction in animals, but otherwise are not 

 dangerous. 



(c) Neurin and hydropyrrolic bases. They are the most abundant 

 leucomains in meat, and are the most poisonous. Minute doses in 

 mice produce dyspnoea, spasmodic movements of the extremities, 

 bristling of the hair, paralysis, tetanic convulsions and death. The 

 presence of neurin as a muscle constituent may well be questioned 

 especially since Gulewitsch has been unable to find it in fresh brains. 



(d) Creatin bases. These produce in mice vomiting, diarrhoea, 

 tetanic convulsions followed by paralysis of the extremities. 



Oruso-creatinin, C^HgN^, forms orange yellow crystals which 

 are slightly alkaline in reaction and possess a somewhat bitter taste. 

 It yields a soluble, non-deliquescent hydrochlorid crystallizing in 

 bundles of needles ; also a soluble platinochlorid which forms tufts 

 of beautifiil, slender prisms. The aurochlorid is obtained as slightly 

 soluble, crystalline grains, and, like the platinum double salt, is 

 partially decomposed on heating. It is not precipitated by acetate 

 of zinc or by mercuric nitrate, but is precipitated in the cold by 

 solutions of alum. Zinc chlorid produces in somewhat concentrated 

 solutions a pulverulent precipitate which dissolves on heating, and 

 recrystallizes again on cooling. Like xantho-creatinin, it is not 

 thrown out of solution by oxalic or nitric acid, and is thus dis- 

 tinguished from urea and guanidin ; nor is it precipitated by acetate 

 of copper — a distinction from xanthin derivatives. Mercuric chlorid 

 produces an abundant flocculent precipitate which on heating partially 

 dissolves, decomposing at the same time. Sodium phosphomolybdate 

 gives a heavy yellow precipitate, whereas potassium mercuric chlorid 

 and iodin in potassium iodid have no effect. Potassium ferricyanid 

 is not reduced. This base differs in its composition from creatinin 

 by HON, the elements of hydrocyanic acid, but in its crystalline 

 form and alkaline reaction, and some other properties, it would seem 

 to be closely related to this latter substance. Because of this ap- 

 parent relationship and its golden-yellow color, Gautier named it 

 cruso-creatinin. 



Xantho-creatinin, CjHj„N^O, is said to be the most abundant of 

 muscle leucomains. It crystallizes in sulphur yellow, thin spangles, 

 consisting of nearly rectangular plates which resemble somewhat those 

 of cholesterin. It is soft and talc-like to the touch ; possesses a 

 slightly bitter taste, and when dissolved in boiling alcohol it gives 



