CBOLIN. 299 



Schmidt. Neurin can be changed into cholin, and vice versa cholin 

 can be changed into neurin (page 290). 



Whether the change described by Baeyer takes place or not, it is 

 nevertheless certain that cholin does not readily give up a molecule 

 of water, and thus become converted into neurin. Ch. Gram an- 

 nounced, in 1886, that cholin chlorid and lactate, on heating on the 

 water-bath with dilute hydrochloric acid, decompose and that this 

 conversion into the vinyl base was easy and complete when the aque- 

 ous hydrochloric acid solution of cholin platinochlorid was heated 

 for five or six hours on the water-bath. In this way Gram endeav- 

 ored to explain the formation of neurin as due to the action of acids 

 upon cholin, but Brieger has shown that the platinum salt of cholin, 

 as well as its hydrocUorid, can be heated with fifteen or thirty per 

 cent., or even concentrated hydrochloric acid for six or eight hours 

 without undergoing any change into neurin, thus disproving the re- 

 sults obtained by Gram. E. Schmidt and Weiss have independently 

 confirmed Brieger's observations in regard to the resistance of cholin 

 to decomposition by acids. Schmidt has gone further, and has 

 shown by an examination of Gram's original preparations that it was 

 cholin and not neurin. Gulewitsch (1894) was likewise unable to 

 split up cholin by acids into neurin. What the action of acids has 

 failed to do is probably accomplished through the agency of bacteria. 

 Schmidt found that cholin chlorid, when allowed to stand with hay 

 infusion, or with dilute blood, for fourteen days at 20°— 30°, decom- 

 posed almost entirely, yielding large quantities of trimethylamin and 

 a base, the platinochlorid of which resembles in form and solubility 

 the double salt of neurin and possesses a similar physiological action. 

 When allowed to decompose for ten days at 30°- 33° neither cholin 

 nor neurin was present. Cholin lactate in hay infiision developed an 

 odor of trimethylamin in twelve hours, but at the end of fourteen 

 days a good deal of cholin was still present. In this case no neurin 

 was present, but instead a homologous base was found which can be 

 obtained synthetically by the action of trimethylamin on allyl bro- 

 mid. According to Meyer, of Marburg, this base does not possess 

 the muscarin-like action of neurin, but resembles more closely pilo- 

 carpin. 



The decomposition of cholin by putrefaction into neurin, and pos- 

 sibly muscarin, highly poisonous bases, may explain the production 

 of poisons in foods. Nesbitt has in like manner endeavored to show 

 that intestinal auto-intoxication may be due to the formation of neu- 

 rin out of the cholin derived from the food lecithin (p. 291). The 

 similar view that mental disorders might be due to neurin formation 

 in the brain led Gulewitsch (1899) to examine the leucomains of 

 perfectly fresh brain. He obtained cholin, two bases (possibly di- 

 amins) and urea, but no neurin. Neither was he able to confirm 

 Liebreich's view that protagon gave neurin (p. 290). 



