108 PROTEIN POISONS 



protein part might be entirely separate from the poison. 

 A sample was precipitated with phosphomolybdic acid 

 in acid solution, the precipitate removed, washed, and 

 dissolved in ammoniacal water. This solution was then 

 shaken with amyl alcohol, but the alcohol was not colored 

 and the residue obtained on concentration was so slight as 

 to be practically nothing. Another sample was precipitated 

 with phosphotungstic acid, the solution being acid in 

 reaction. The precipitate was allowed to settle, removed 

 by filtration, washed with acidulated water, decomposed 

 with a saturated solution of barium hydrate, and the 

 remaining insoluble part filtered out. So far as possible, 

 the barium was removed from the filtrate with carbon 

 dioxide, alternating with concentration, and further addi- 

 tion of carbon dioxide. The solution was then allowed to 

 concentrate to dryness, when the residue was dissolved in 

 absolute alcohol, leaving barium salts behind. On con- 

 centrating the slightly opalescent solution, more barium 

 salts came down during the process and were filtered out. 

 The dry residue was taken up in water and ammonium 

 carbonate used to precipitate the barium that still remained. 

 After removing the barium carbonate by evaporating on 

 the water-bath, both carbon dioxide and ammonia were 

 expelled, the solution again becoming acid. Dryness being 

 reached, absolute alcohol was once more used, leaving 

 undissolved a small amount of inorganic material. In this 

 way the final residue after evaporation of the alcohol was 

 practically freed from inorganic impurities. Sulphuric 

 acid no longer gave a barium precipitate in water solution. 

 The amount obtained by this method w r as very small and 

 an exceedingly small part of the original toxic powder. 

 Since the substance obtained in this way still gave good 

 Millon's, biuret and xanthoproteic reactions, it is fair to 

 say that it was not alkaloidal. The very small amount 

 obtained by this method given to a guinea-pig intra- 

 abdominally made the animal sick, but did not kill. 

 Either phosphotungstic acid does not precipitate the toxic 

 body or else the amount obtained was less than a fatal 

 dose. 



