288 CHEMISTRY OF THE PTOMAINS. 



that ^-amido-valerianic acid agrees with this base in its reacti6ns to 

 copper nitrate. The gold salt of the synthetic base possessed the 

 same composition as that of Salkowski, and melted at 86°- 87°. 



The identity of this base with 5-amido-valerianic acid (homo- 

 piperidinic acid) would seem to be established, and as such it is 

 regarded. Its structure, then, is represented by : 



NH,. CK,. CH^. CHj. CHj. COjH. 



For its synthetic preparation, see Ber., 24, 1365 (1891). The base 

 does not seem to possess toxic action. 



The hydrochlorid, CjHjjNOj.HCl, forms colorless, stellate crys- 

 tals, which are permanent in the air, and are extremely soluble in 

 water, even in absolute alcohol. 



The aurochlorid, CjHuNO^.HCl.AuClj + H^O, is obtained on slow 

 evaporation, as large, well formed, beautiful dark yellow crystals. 

 They are probably monoclinic, contain water of crystallization and 

 melt at below 100°. 



The platinochlorid gave on analysis results corresponding to the 

 formula (CyHjj.N02.HCl)2PtCl^. This possibly may have been due 

 to the presence of some higher homologues of the base C^Hj^NOj. It 

 forms fine orange-yellow crystals, which are very difficultly soluble 

 in alcohol, easily so in hot water, from which, on cooling, it crystal- 

 lizes in beautiful plates. 



Gholin Group. — The following four bases are closely related, and, 

 indeed, starting from cholin, the oldest and best known individual, 

 the remaining bases can be readily prepared from it. Moreover, 

 they can all be prepared synthetically according to methods that 

 will be subsequently indicated. As cholin is the most prominent 

 member, we have thought best to class these substances together as 

 constituting the cholin group. It is very probable that mydatoxin 

 and mytilotoxin, when their constitution becomes known, will be 

 found to be homologues of certain members of this group. 



Neurin, C^HjjNO = C2H3.N(CH3)3.0H.— This substance was ob- 

 tained and named thus by Liebreich (1865), who prepared it by 

 boiling protagon for twenty-four hours with concentrated baryta. 

 Previous to its discovery as a decomposition product of protagon 

 from the brain it was prepared synthetically by Hoffinann (1858) 

 by treating trimethylamin and ethylene bromid with potassium hy- 

 drate or silver oxid. Baeyer (1866), by boiling an alcoholic ex- 

 tract of the brain with baryta water, obtained, on separation by 

 three different methods, a base or rather a mixture of bases, which 

 on analysis gave results corresponding to the three formulae : 



1 2 3 



{C5Hi4NOCl),Pta4 (CjHijNCl)jPtCl4 (C5H„NCl),PtCl4 



