300 GHEMISTBY OF THE PTOMAINS. 



Brieger (I., 59) had unsuccessfully tried to transform eholin into 

 neurin by putrefaction. He observed that the eholin decomposed 

 with extreme slowness, even when the putrefaction was carried on at 

 a higher temperature, yielding only trimethylamin. Wurtz (1868) 

 showed that dilute solutions of free eholin can be heated to boiling 

 without any perceptible decomposition. Concentrated solutions, 

 however, decompose with the formation of trimethylamin and glycol, 

 CjH^(OH)j (see page 250). The decomposition of eholin was studied 

 somewhat by Mauthner (1873) who confirmed Wurtz's observation 

 that eholin was scarcely decomposed by boiling water, and he showed 

 that when exposed to the action of decomposing blood it yielded 

 trimethylamin. The results obtained by K. Hasebroek {Zdtsohrift 

 f. physiol. Chem., 12, 151, 1888) deserve special mention at this 

 place. He carried on the putrefaction of very dilute solutions of the 

 chlorid of eholin in the presence of little or no oxygen in Hoppe- 

 Seyler fermentation flasks. Sewer slime, because of its strong fer- 

 mentative properties, was used to induce the putrefaction, and cal- 

 cium carbonate was added to neutralize any acidity that might 

 develop during the fermentation. 



The fermentation, as shown by the evolution of gases, lasted for 

 about three months. The total quantity of gas given off was about 

 one liter from 1.17 grams eholin chlorid. The gases consisted almost 

 entirely of carbonic acid and marsh gas. No hydrogen was evolved. 

 When the fermentation ceased the flask was opened and several cubic 

 centimeters of the almost neutral clear liquid were injected under 

 the skin of a rabbit without producing the least effect. 



This liquid distilled with alkali gave methylamin and ammonia. 

 What is remarkable about this experiment was the total absence 

 of the higher amins — as, for instance, trimethylamin, which has been 

 observed so many times as a decomposition product of eholin. The 

 absence of any poisonous base, as neurin, was probably largely 

 connected with the absence of oxygen. 



Free eholin ordinarily forms a strongly alkaline syrup which com- 

 bines readily with acids to form salts, most of which are deliquescent. 

 By oxidation it is converted into betain (see page 305), and on treat- 

 ment with concentrated nitric acid it gives rise to a muscarin (see 

 page 309). These reactions can be represented by the equations : 



CO. 



OH 



CH, +0,= CH, +H,0. 



N(CHs)s.OH N(CH,)3.0H 



CHOI/IN. Betaih. 



+ O = ^HOH 

 N(CH3),.0H 



MUSOASIH. 



