Further experimenta» however, showed that on extracting the 

 poisonous guai with 50/o alcohol, a portion of it dissolved, 

 and this solution gave a precipitate with lead acetate which 

 was a true lead compound. The remainder of the purified 



tar (about lOgm. ) was treated with 5O7S alcohol and filtered. 

 Very little dissolved in alcohol of this strength, hut on 

 addition of lead acetate in BOji alcohol to the solution, 

 a light colored precipitate was formed, which hecame dark 

 on standing. It waS filtered off, washed free from lead 

 acetate, decomposed by hydrogen sulphide, and shaken out 

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

 substance having a faint odor like garlic. By drying in a 

 dewiccator, a small quantity of a solid yellow resin was 

 obtained v;hich was completely soluble in alcohol. A very 

 small drop of this solution applied to the skin on the end 

 of a glass rod which had been dr\¥n out to a point caused an 

 eruption in about thirty-six hours. Follov/ing the nomen- 

 clature used by liaiach and Pfaff, this substance will be 

 designated as Toxicodendrin . the ending "in" indicating its 

 glucoside nature. 



The filtrate from the lead precipitate just described was 

 freed from, the excess of lead acetate by hydrogen sulphide, 

 was tested for poison, and was found to be poisonous, showing 

 that the precipitation by lead acetate was not complete even 

 in 50^ alcohol. On spontaneous evaporation of the solutioa., 



-49- 



