286 PROTEIN POISONS 



just as marked in those under the influence of the protein 

 poison. 



6. Our poison is the active principle in peptone, and 

 when it has been extracted from peptone the residue is no 

 longer poisonous. 



7. When the poison has been removed from an anaphyl- 

 actogen the residue may or may not sensitize, but in 

 no case does it induce the symptoms of anaphylaxis on 

 reinjection. 



8. The activity of the protein poison is progressively 

 increased to a certain point in proteolytic digestion. Peptone 

 is more poisonous than the protein from which it is formed, 

 and the same is true of some of the products of tryptic 

 digestion. The protein poison in ordinary proteins is not 

 active because it is combined with other groups, and as 

 these groups are detached it becomes more and more 

 poisonous. The protein molecule is a highly complex 

 organic compound made up of many groups, some of which 

 are basic, and some acid in character, and at least one which, 

 when detached from the others, is highly poisonous, and it 

 is poisonous because of the avidity with which it disrupts 

 the proteins of the body. To make it simpler we may say 

 that the protein molecule is a neutral or basic salt, and as 

 the basic elements are split off it becomes an acid salt, and 

 finally a free acid, and with each step its poisonous action 

 increases because its capability of depriving other salts of 

 their basic elements increases. Finally the acid, itself a 

 complex body, becomes disrupted and looses its poisonous 

 properties. 



9. Since proteolysis is a progression in which complex 

 molecules are broken into simpler and still simpler ones, in 

 all proteolytic digestion there is an increase in the activity 

 of the protein poison up to a given point, when it ceases to 

 be a poison. It follows, therefore, that whatever the specifi- 

 city of the proteolytic ferment, at some stage in the process 

 the poison is more or less freed from the groups which tend 

 to prevent its action. The protein molecule has definite 

 lines of cleavage, and is disrupted only along these lines, 



