Vaughan's Split Products and Unbroken Proteins. 75 



sensitized guinea pigs, no protection resulted. Lecithin given, in 

 doses from 250 to 500 milligrams or more, to serum sensitized 

 guinea pigs protects them from a second injection of 5 c.c. horse 

 serum given twenty hours later. 



Lecithin {Egg) Effect on the Poison. 

 Neither when emulsified with the poison ; nor given as a pre- 

 liminary injection, followed by the egg-white poison, twenty hours 

 later, was there any protection afforded. The difference in the 

 protective action of preliminary doses with the serum and with the 

 poison, we think, is due to the absorption by the lecithin of the 

 ferment in the sensitized guinea pig which causes the splitting of 

 the whole protein, thus preventing the cleavage and liberation of 

 the poison. 



In the case of the poison, this cleavage has been done in the 

 retort, and as the lecithin does not protect against the poison itself, 

 death occurs as in control animals. Apparently this supposed ab- 

 sorption of ferment by the lecithin takes place slowly for if the 

 lecithin and serum are injected simultaneously death occurs 

 typically. 



Eighteen to one hundred hours after the inoculation of 500 

 milligrams of lecithin the serum sensitized animals were protected 

 from the second injection of 5 c.c. horse serum. Thus far these 

 are the time limits, after the injection of lecithin, that we have 

 allowed before giving the second injection. 



We assume, with Banzhaf and Famulener, that chloral allows 

 the ferment or zymogen in a sensitized guinea pig to split the 

 protein, but protects the animal's vital cells from the action of the 

 poison, and similarly protects the normal guinea pig from 

 Vaughan's split poison. 



The Residue. 



1. The sensitizing action of Vaughan's residue (egg-white) 

 differs with different products. Two out of three were inactive. 

 This inactivity may be due to the heat used in the Vaughan 

 method. In fact the loss of the toxic properties of the residue 

 can be fully explained through the action of the heat alone, irre- 

 spective of any cleavage of the molecule due to the alcohol and 

 sodium hydroxide used. 



