CII KM 1ST HY OF THK PTOMAINKS 



the methods of extraction, and, indeed, lie claimed to have 

 converted clioline platinochloridc, by heating with hydro- 

 chloric acid, into neiirine. This statement has been dis- 

 juited lv I)i;iH(iKU, who showed that the platinochloridc 

 of choline, as well as the hydroehloride, may 1)0 heated 

 with fifteen or thirty per cent., or even concentrated hydro- 

 chloric acid, for six to eight hours on a water-bath, with- 

 out any conversion whatever (HI., 15). That neurine 

 mav In- obtained from choline, at least by chemical pro- 

 . was shown by I>.U:YKH, in 1800, who found that 

 choline chloride, when heated with several times its volume 

 of concentrated hydriodie acid and some red phosphorus, 

 gave a compound C 5 H 13 X L which, on digestion with fresh, 

 moist silver oxide, yielded a vinyl base identical with that 

 previously obtained synthetically by HOFMAMN, and now 

 known as neurine. BUIJ-XJKK has tried, unsuccessfully, to 

 bring about this dehydration by the putrefaction of pure 

 choline (I., 59). However, SCHMIDT and WEISS (1887) 

 were more successful, and they found that choline, as well 

 as the hydroehloride and lactate, is changed by the action 

 of microorganisms into the strongly poisonous neurine. 

 Their results are given in full under choline (see page 244.) 

 From what has been said it is evident that neurine can 

 only arise from choline, and this, as will be seen later, is 

 derived from lecithin. 



Neurine is almost invariably accompanied by choline, 

 from which, however, it can be readily separated by the 

 dill'erence in the solubilities of the platinochlorides. It 

 occurs in the mercuric chloride precipitate (and in the 

 iiltrate), and from this it can be obtained, after removal of 

 the mercury, by precipitating the solution of the mixed 

 hydrochlorides in absolute alcohol by platinum chloride. 

 The platinochlorides are then separated by recrystalli/ation 

 from water, since the neurine is difficultly soluble, while 

 the choline salt is readily soluble. 



The five base possesses a strong alkaline reaction, and 

 on contact with the fumes of hydrochloric acid it yields a 

 cloud. According to LIKHKKK n, the alkaline solution 

 cannot be neutrali/cd by passing through it carbonic acid. 



