DELPHININE. 185 



tion of alcoholic potassium hydrate, is not affected by the 

 presence of ptomaines. On the other hand, the character- 

 istic odor produced by the action of sulphuric acid and 

 heat on atropine is scarcely recognizable when ptomaines 

 are present. 



Naeceine. — The blood-red color produced by concen- 

 trated sulphuric acid fails in the presence of ptomaines. 



Colchicine. — Fuming nitric acid colors the ptomaines 

 reddish-yellow, but the violet coloration of colchicine with 

 nitric acid appears in well-defined form, even iu the pres- 

 ence of ptomaines. The other reactions for colchicine are 

 valueless when ptomaines are present. 



Codeine. — The blue coloration of codeine with concen- 

 trated sulphuric acid holds good when ptomaines are present. 

 The same is true of the reaction with sulphuric acid, heat, 

 and the subsequent addition of nitric acid. Frohde's re- 

 agent fails with codeine when mixed with ptomaines, inas- 

 much as the bluish coloration rapidly passes into a brown. 



AcONiTiNE. — Phosphoric acid and concentrated sulphuric 

 acid are without reaction on the alkaloid when mixed with 

 ptomaines. 



PiCROTOXiNE. — The reducing action of picrotoxine on 

 alkaline copper sulphate solution is seriously affected by the 

 presence of ptomaines. The same is true of other tests for 

 this poison. 



Delphinine. — The reaction of delphinine with sulphuric 

 acid and bromine water, as well as the one with Frohde's 

 reagent, is so much influenced by the presence of ptomaines 

 that the alkaloid cannot be recognized. 



These results are to be accepted with caution, as it is not 

 reasonable to suppose that all ptomaines will affect the test 

 for the vegetable alkaloids in the same manner or to the 



