54 THE SIMPLER NATURAL BASES 



Choline, Trimethyl-/3-hydroxy-ethyl-ammonium Hydroxide, 



XT 



IN 



/OH 



\CH.CHOH. 



Strecker [1849] obtained from pig's bile the platinichloride of 

 a base, of which he later [1862] published the formula and a further 

 description, and which he then named choline. Meanwhile von Babo 

 and Hirschbrunn [1852], by hydrolysis of the alkaloid sinapin from 

 white mustard seeds, had prepared a strong base which was well 

 characterised by its platinichloride and was named sinkalin (from 

 Sinapis and alkali). The identity of the base from mustard with 

 that from bile was established by Claus and Kees6 [1867], but never- 

 theless Strecker's (later) name has passed into general use. Con- 

 fusion was introduced when Liebreich [1865] obtained a base by 

 the hydrolysis of the brain substance protagon, and termed it 

 neurin. The analysis of an impure platinichloride led Liebreich 

 to the erroneous formula C 5 H 12 ON, corresponding to vinyl-trimethyl- 

 ammonium hydroxide, and to this substance the name neurine has 

 become definitely attached. The identity of Liebreich's protagon 

 base with choline was established by Dybkowsky [1867] and for 

 some years neurine was used as a synonym for choline, to which 

 the name bilineurine was at one time also applied. The true formula 

 of Liebreich's "neurin" was determined by Baeyer [1866, under 

 neurine] who also converted it into the vinyl base [1869, under 

 neurine], and " nevrine " (= choline) was first synthesised by Wurtz 

 [1867]. 



Since choline is a constituent of lecithin, it occurs probably in all 

 living cells. It has been isolated by Schulze and his collaborators 

 from every plant extract examined by them for its presence [Schulze 

 and Trier, 1912, 3]. Choline has been found in the following 

 tissues : 



In the brain: as phosphatide, Liebreich [1865], Gulewitsch [1908, i], Vincent and 

 Cramer [1904], Cramer [1904], Coriat [1904], Thudichum [1884, 1901 ; under amino-ethyl- 

 alcohol] ; it is not present in the free state, Kauffmann [ign]. In the cerebro-spinal fluid 

 in disease (Mott and Halliburton [1899] ; see below for an account of the controversy on 

 this point). In many viscera (Kinoshita [1910, 2]), in the adrenal gland (Hunt [1899-1900], 

 Lohmann [1907, 1911]), in the thymus, thyroid and lymphatic glands, and in the spleen 

 (Schwarz and Lederer [1908]), in blood and in serum (Letsche [1907; Ch. IV, creatine], 

 Gautrelet and Thomas [1909]), in ox testes (Totani [1910, i]), in semen (Florence [1897]), 

 in egg-yolk, the most convenient natural source (Diakonow [1868]), in autolysed pancreas 

 (Kutscher and Lohmann [1903]), in meat extract (Kutscher [1906, i ; Ch. V, creatine]), in 

 putrid horse meat (Gulewitsch [1884, Ch. I]), in human corpses (Brieger [1885, 2, p. 17; 

 Ch. I]), in bile (Strecker [1849]), in secretine (von Fiirth and Schwarz [1908]), in cheese 

 (Winterstein [1904]), in herring brine (Bocklisch [1885, Ch. 1]), in salted fish (Morr.er 



