102 PROTEIN POISONS 



The brownish toxic powder, varying in shade of color 

 somewhat with the protein from which it has been obtained, 

 has a peculiar odor. It is highly hydroscopic, and the 

 poisonous .portion is freely soluble in water. The solubility 

 of the whole powder, however, varies with the protein 

 from which it is obtained, and possibly with the length 

 of time that it has been exposed to the alkali in the alcohol. 

 Any portion insoluble in water should be removed by 

 filtration, and in some instances we have found filtration 

 through porcelain necessary. Generally the powder dis- 

 solves in water with a slight opalescence easily removed by 

 filtration through paper. In all cases we have found the 

 portion insoluble in water free from toxic effect. Aqueous 

 solutions of the poison are decidedly acid to litmus, the 

 acidity being due to some organic body and probably 

 not to the poison itself. On neutralization with sodium 

 bicarbonate a brownish, non-toxic precipitate is formed. 

 Prolonged contact with alkali, as we shall see later, lessens 

 the activity of the poison, and even neutralization has 

 some effect, which is more marked the longer the prepara- 

 tion stands. We are inclined to attribute this to the forma- 

 tion of a salt with the acid poison and the alkali. The 

 poison is freely soluble in alcohol, more readily than in 

 water. Alcoholic solutions on long standing deposit small 

 brownish sediments which we have always found to be 

 inert. When an alcoholic solution is evaporated, there is 

 a part of the residue that is insoluble in absolute alcohol. 

 These portions also are devoid of toxic effect. Alcoholic 

 solutions have been kept for five years without recog- 

 nizable loss in toxicity, and even aqueous solutions decom- 

 pose very slowly. The poison is soluble in methyl as well 

 as in ethyl alcohol. It is insoluble in ether, chloroform, 

 and petroleum ether. Each of these removes a small 

 amount of fatty substance, which is non-toxic, but they 

 do not dissolve an appreciable quantity of the poison. 

 From its alcoholic solution the poison is precipitated by 

 ether, but contact with ether decreases its toxicity to such 

 an extent that this method is not applicable in attempts 

 at purification. 



