187 



100-00 100-00 



A sami^le of picrotoxin purchased some time ago was subjected 

 to various modes of treatment, Ijeing recrystallised in different 

 ways, and gave the following percentage of carbon and 

 hydrogen : — 



Cai^bon ... 60-66 61-06 60-10 61-90 60^79 

 Hydrogen... — 6-31 5-78 6-20 5-91 



It will be seen that the figures obtained by us for the substance 

 from Stejyliania come well within the limits of those obtained 

 from different samples of genuine picrotoxin. We have no doubt 

 whatever, therefore, that the crystalline substance obtained as 

 above described from Stephania-voots is picrotoxin, or a mixture 

 of picrotoxin and picrotoxinin. Dr. Stirling kindly injected 

 some of the aqueous solution into the dorsal lymph sac of a frog. 

 Violent convulsions speedily set in, resulting in death — a result 

 quite in accordance with the known jDhysiological effects of 

 picrotoxin. 



There was, however, reason to suspect that some other poison- 

 ous matter was present in the roots besides that just described. 

 The acid liquid, therefore, from which the picrotoxin had been 

 thoroughly extracted by chloroform, was made alkaline with 

 caustic soda. This caused the precipitation of a substance 

 which, however, dissolved in excess of soda, but was partially 

 reprecipitated on the addition of sodium bicarbonate. The 

 precipitate was filtered off, and the alkaline solution extracted 

 with ether. The ether, on evaporation, left a yellow amorphous 

 mass which gave all the characteristic reactions of an alkaloid ; 

 but from which no crystalline salts could be obtained. Its chief 

 chemical characteristic was the brilliant green colouration which 

 it gave on the addition of strong sulphuric acid. "We at first 

 suspected the presence of herberine, but all efforts to isolate this 

 alkaloid have so far failed. The yellow alkaloid was not obtained 

 in sufficient quantity for analysis. It is very easily decomposed ; 

 for instance, if dissolved in dilute acetic acid and evaporated on 



