12 Fractionation of Phosphotungstic Acid Precipifate 



moved with lead acetate and the excess of lead with hydrogen sulfid. 

 The last filtrate was evaporated to dryness in vaciio, the residue dis- 

 solved in alcohol and precipitated with alcoholic mercuric chlorid 

 sol. 



Mercuric chlorid precipitate. The 14.4 gm. of mercuric chlorid 

 precipitate obtained by the foregoing treatment were suspended in 

 water, decomposed with hydrogen sulfid, and the filtrate evaporated 

 to dryness in vaciio. The residue was dissolved in water, freed 

 from chlorin with silver acetate, the silver removed with hydrogen 

 sulfid and the filtrate evaporated, yielding o.i gm. of crystallin sub- 

 stance which was not investigated further. The filtrate from this 

 substance was precipitated in alcoholic sol. with platinic chlorid ; 3.9 

 gm. of a very insoluble platinum salt were obtained. This salt was 

 recrystallized from water. After decomposition with hydrogen 

 sulfid and subsequent evaporation it yielded crystals which, dried in 

 vacuo at iio°C., blackened when heated over 200° but did not melt 

 even at 300° (uncorr.). The estimation of platinum did not give 

 constant results; 44.8 percent and 42.5 percent were obtained. 



The filtrate from the salt was freed from platinum and evap- 

 orated in vacuo. The residue gave no precipitate with picrolonic 

 acid, nor with mercuric acetate, sulfate or nitrate. 



Mercuric chlorid filtrate. The filtrate, freed from mercury, 

 yielded, by evaporation, a crop of crystals weighing i.i gm. The 

 filtrate from this substance was evaporated in vacuo. The residue, 

 dissolved in alcohol and precipitated with platinic chlorid, yielded 

 1.9 gm. of the salt; this has not as yet been investigated. The fil- 

 trate from the salt, freed from platinum, gave no picrolonate. 



The investigation of all these fractions is in progress. The 

 acetone-insoluble fraction was active, as has been stated elsewhere 

 (10). 



4. Fractionation of autolyzed yeast. Two k. of pressed 

 baker's yeast were moistened with water and left for 48 hr. at 37°C. 

 To the mixture an equal vol. of alcohol was added, the liquid fil- 

 tered, the residue washed, and the filtrate and washings evaporated 

 in vacuo to dryness. To the residue, 500 cc. of 10 percent sulfuric 

 acid sol. were added and allowed to stand over night. On the fol- 

 lowing day 500 cc. of water were added, the resultant precipitate 



