■bone-tlack and the filtrate was apparently pure alcohol and 

 wat er. 



In precipitating an alcoholic solution of the crude ma- 

 terial with a solution of lead acetate, it was noticed that at 

 least two kinds of precipitates were formed. The part that 

 went down first wa-, darker in color than thatrthJrown down later, 

 Pfaff used the last fractions in ohtaining his oil and stated 

 that these precipitates consisted of the lead compound of the 

 oil in a pure state. It was found by experiment that the 

 darker part was soluble in ether while the lighter part was not. 

 This indicated that the darker part ccr.alsted of tarry - "-tter 

 which was brought down mechanically or separated out cTv ihe 

 dilution of the alcoholic solution l, une lead acetate solution, 

 or was perhaps a lead compund soluble in ether. To test this 

 point an experimerit was made as follows: Some of the crude 

 material was thoroughly extracted with 50^ alcohol. The tar 

 insoluble in 5Gfo alcohol was then treated with 25% alcohol; 

 most of it dissolved; the solution was filtered and lead 

 acetate in 50^ alcohol was added. A greenish colored preci- 

 pitate was formed which was filtered off and found to be com- 

 pletely soluble in ether and soluble to a considerable extent 

 in strong alcohol. These experiments suggested that the 

 li^t colored lead compound which was thought to contain the 

 poison could be purified by extraction with ether in a Soxhlet 

 apparatus more conveniently than by the tedious process of 



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