58 NERVOUS SYSTEM. 



in alcohol. When incinerated it does not leave a residue 

 impregnated with phosphoric acid, like the cerebral fatty 

 matter. 1 According to more recent investigations, particu- 

 larly those of Liebreich, neurine is a derivative of protagon. 

 The neurine of Liebreich is obtained by boiling protagon for 

 twenty-four hours in baryta-water, when there is formed the 

 phospho-glycerate of baryta, and a new base, neurine. 8 It is 

 evident that this substance cannot properly be regarded as a 

 well-determined proximate principle. 



"We have already alluded to the experiments of Wurtz 

 upon the synthesis of neurine. 3 These observations are im- 

 portant as a step toward the synthesis of organic nitrogen- 

 ized principles, but they do not afford an example of the 

 actual formation of a characteristic nitrogenized constituent 

 of the nerve-tissue. They simply show that the chlorohy- 

 drate of an artificial organic compound presents crystals 

 identical with the chlorohydrate of neurine extracted from 

 the brain. 4 



Cerebral Fatty Principles. Researches into the compo- 

 sition of the fatty principles found in the nervous substance 

 have been so indefinite and unsatisfactory in their results, 

 that even now they possess but little physiological interest. 

 In the earlier observations, the fats extracted from the nerve- 

 tissue were generally combined with cholesterine. This sub- 

 stance has now been isolated, and the residue contains a 

 variety of principles, which seem, under physiological condi- 



1 KOBIN ET VERDEIL, Traite de chimie anatomique, Paris, 1853, tome iii., 

 p. 451. 



2 LIEBREICH, loc. cit. ; and, Journal de Vanatomie, Paris, 1866, tome iii., p. 654. 



3 See vol. iii., Excretion, p. 195, foot-note. 



4 WURTZ, Sur Vldentite de la nevrine artifiddle avec la nevrine naturdle. 

 Comptes rendus, Paris, 1868, tome Ixvi., p. 772, et seq. Wurtz obtained neurine 

 by the reaction of trymethylamine upon monochlorohydric glycol. He found 

 that the chlorohydrate of trymethyloxethylammonium was identical with the 

 chlorohydrate of neurine prepared with neurine from the brain. By neurine, 

 Wurtz undoubtedly means the principle described under that name by Liebreich. 



