contain lead. Thinking that the lead acetate had not heen 

 completely washed out, the main part of the tar was dissolved 

 in ether and shaken with watjer. The wash water continued to 

 give a test for lead as long as the washing was continued. 

 This indicated probably the hydrolysis of an unstable lead 

 compound. Hydrogen sulphide was passed into the ether solution 

 mixed with water to raiiove the lead. Lead sulphide was filtered 

 off, and the ether was evaporated, A small portion of the tar 

 residue in alcoholic solution gave a color reaction with ferric 

 chloride. As this may have been due to traces of lead gallate 

 dissolved in the extraction with ether and afterwards decom~ 

 posed by hydrogen sulphide, the main portion of the tar was 

 redissolved in ether and shaken with water until it no longer 

 reacted with ferric chloride. The ether was then evaporated 

 and a soft, black, poisonous tar or gum of uniform consistency 

 was left which was shown by tests to be free from gallic acid and 

 lead. These experiments showed that some of the poison was 

 precipitated as a lead compound soluble in ether and some was 

 brought down mechanically in the free state. To see if the 

 extraction with ether in the Soxhlet apparatus was complete, 

 the residue from in the thimbles was decomposed by hydrogen 

 sulphide and shaken v/ith ether. The dark colored ether solu- 

 tion was freed from gallic acid by shaking with water and dilute 

 sodium carbonate solution, and was evaporated, A small 

 -44- 



