236 METHODS OF EXTRACTING PTOMAINS. 



lactate of cholin, an inert substance which is widely distributed both 

 in plants and animals, is heated, it is converted into a poison which 

 has a muscarin-like action. However, Brieger obtained some of 

 his bases by a much simplified modification of his complete method ; 

 for instance, in obtaining neuridin, he treated the aqueous extract of 

 the putrid material, after boiling and filtration, with mercuric chlorid, 

 collected the precipitate, decomposed it with hydrogen sulphid, evap- 

 orated the filtrate on the water-bath, and extracted the base from the 

 residue with dilute alcohol. Brieger's method is only a modification 

 of that employed by Bergmann and Schmiedeberg as long ago as 

 1868 in the preparation of sepsin from putrid yeast. 



