CHEMISTRY OF THE PTOMAINES. 243 



Decompositions of Choline. — Baeyer (1866) suc- 

 ceeded in convertiug choline into neuriue by a purely 

 cliemical process. This was accomplished by heating 

 choline chloride with concentrated hydriodic acid and 

 red phosphorus in a sealed tube at 120°-150°, whereby 

 the compound C5H13NI2 was formed. The iod-iodide of 

 choline thus obtained, on treatment with moist silver oxide, 

 gave a base whose platiuochloride corresponded to the 

 formula (C.H.jNCO.PtCl. + H/:). This double salt, ac- 

 cording to Baeyek, is readily soluble in water, and gives 

 reactions similar to choline. Although Baeyer is em- 

 phatic in his assertion that this is the vinyl compound 

 (neurine) formed from the oxy-ethyl base (choline), yet it 

 seems that there is room for doubt in regard to the 

 interpretation of his results. Thus neurine platiuochloride 

 is difficultly soluble in water, coutrary to the behavior of 

 the platiuochloride obtained by him. On the other hand, 

 choline platiuochloride is easily soluble in water, and it 

 would seem, therefore, that Baeyer has not converted 

 choline into neurine, but rather has regenerated choline 

 from its iod-iodide. If such were the case, we would ex- 

 pect that the iod-iodide of neurine, C5H,3Nr2, which has 

 the same composition as the corresponding derivative of 

 choline, would yield, on treatment with silver oxide, the 

 oxy-ethyl base. Bakyer has apparently not been able to 

 effect this change, since he holds that the vinyl base may 

 be prepared from the oxy-ethyl, but that the reverse, tlie 

 preparation of the oxy-ethyl base from the vinyl' compound, 

 cannot be accomplished. 



Whether the change described by Baeyei". takes place or 

 not, it is, nevertheless, certain that choline does not readily 

 give up a molecule of water and thus become converted 

 into neurine. Ch. Gram announced, in 1886, that choline 

 chloride and lactate on heating on the water-bath de- 

 compose, and that this conversion into the vinyl base was 

 complete when the aqueous hydrochloric acid solution of 

 choline platiuochloride was heated for five or six hours on 

 the water-bath. In this way CiRAM endeavored to explain 

 the formation as due to the action of acids upon choline, 



