i 4 8 THE SIMPLER NATURAL BASES 



Thzplatinichloride, (C 7 H 15 O 2 N) 2 . H 2 PtCl 6 , is readily soluble in warm 

 water, but hardly in hot alcohol, and forms light red plates, melting at 

 224-225. 



The ethyl ester yields a characteristic platinichloride (C 9 H 19 O 2 N) 2 . 

 H 2 PtCl 6 , melting at 220 (Takeda, Engeland and Kutscher). 



Apart from the synthesis, the constitution is established by the 

 formation of an ester, by the optical inactivity (Takeda) and by the 

 liberation of trimethylamine on distillation with baryta. 



Solutions of the hydrochloride are not precipitated by picric acid, 

 but by phosphomolybdic and phosphotungstic acids, by potassium 

 mercuric iodide, potassium cadmium iodide, and potassium tri-iodide ; 

 in all cases the precipitate, which is at first amorphous, soon crystallises 

 in needles (Brieger). Takeda also observed the gradual crystallisation 

 of the precipitate with potassium bismuth iodide. 



Carnitine. 



This substance is best prepared from meat extract by Gulewitsch and 

 Krimberg's method. After removal of carnosine and other bases by 

 means of silver nitrate and baryta, the solution is freed from silver and 

 barium, and the carnitine is precipitated with potassium bismuth 

 iodide (see p. 121). 



The free base, the hydrochloride C 7 H 15 O 3 N . HC1 and the nitrate 

 C 7 H 15 O 3 N . HNO 3 are all readily soluble in water ; a i o per cent, solution 

 of the hydrochloride in excess of free acid has [a] D = - 20-9. 



The platinichloride, (C 7 H 16 O 3 N) 2 . H 2 PtCl 6 , crystallises from 80 per 

 cent, alcohol in short prisms; m.p. 214-218. 



The aurichloride, C 7 H 16 O 8 N . HAuCl 4 , forms citron yellow needles ; 



m.p. I53-I54 . 



There are two double salts with mercuric chloride : C 7 H 15 O 3 N . 

 2HgCl 2 , from the free base and mercuric chloride, both in alcoholic 

 solution ; sparingly soluble in water and crystallising fairly readily; m.p. 

 204-205. C 7 H 15 O 3 N . HC1 . 6HgCl 2 is formed in the presence of a 

 slight excess of hydrochloric acid ; it is an oil, crystallising with diffi- 

 culty; m.p. 211-215. 



Carnitine ethyl ester, C 9 H 19 O 3 N, was according to Krimberg [1908, 2] 

 mistaken by Kutscher for a new base from meat extract under the 

 name oblitine ; Kutscher gave it the formula C 18 H 38 O 5 N 2 . Krimberg 

 [1907, 2] showed that oblitine is formed by evaporating an alcoholic 

 solution of carnitine with hydrochloric acid, which is one of the steps 

 in Kutscher's process of separation. At first Krimberg considered 

 oblitine to be the ethyl ester of an anhydride, formed from two 



