98 PROTEIN POISONS 



precipitating jar, then poured with constant stirring into 

 four volumes of 95 per cent, alcohol. This stands with 

 frequent stirring for two days, then the alcohol is decanted, 

 and replaced with the same volume of absolute alcohol. 

 This is allowed to stand for from one to two days, when 

 the coagulated albumin is collected on a filter, allowed to 

 drain, then placed in large Soxhlets and extracted with 

 ether for from one to two days. It is then ground in porce- 

 lain mortars and passed through fine meshed sieves. This 

 gives a beautifully white powder w T hich may be kept in 

 bottles in stock from which portions are taken for the 

 purpose of hydrolyzing it. 



Twenty dozen eggs yield about 735 grams of this powder, 

 a little more than 3 grams per egg. 



A weighed portion of the protein, prepared as above, is 

 placed in a flask, covered with from fifteen to twenty-five 

 times its weight of absolute alcohol in which 2 per cent, of 

 sodium hydroxide has been dissolved. The flask, fitted 

 with a reflux condenser, is heated on the water-bath for 

 one hour, when it is allowed to cool and the insoluble portion 

 collected on a filter. After thorough draining the insoluble 

 part is returned to the flask and the extraction repeated. 

 It has been found that three extractions are necessary in 

 order to split off all the poisonous group. The temperature 

 of these extractions is 78, the temperature of boiling 

 absolute alcohol. By this method the protein is split into 

 two portions, one of which is soluble in absolute alcohol 

 and is poisonous, while the other is insoluble in absolute 

 alcohol and is not poisonous. 



A large number of protein bodies, bacterial, vegetable, 

 and animal, have been split up in this way and no true 

 protein has failed to yield a poisonous portion. Among 

 the proteins with which we have worked the following may 

 be mentioned: egg-white, casein, serum albumin, edestin, 

 zein, Witte's peptone, Macquaire's peptone, de Chapoteaut's 

 peptone, the tissue of cancers, and the cellular substance 

 of bacillus coli communis, b. typhosus, b. anthracis, b. 

 tuberculosis, b. Moelleri (timothy), sarcina lutea, b. ruber 



