456 PROTEIN POISONS 



mean that the intracellular ferments have no cleavage 

 action. They chip the rough stone so that it fits in at the 

 right place. It is by virtue of their activity or through their 

 agency that cells grow and multiply. In case of an infec- 

 tious disease the intracellular ferment of the infecting 

 organism during the period of incubation converts man's 

 proteins into bacterial proteins, and continues to do this 

 with more or less success during the course of the disease. 

 This seems to be accomplished in pome diseases, at least, 

 like typhoid fever, without any marked disruption of the 

 cells of the man's body. The bacteria multiply rapidly 

 during the period of incubation, and at this time the man is 

 unconscious of the fact that his body is serving as a culture 

 flask. We must conclude from this that the conversion of 

 human proteins into typhoid proteins in the growth of the 

 infecting agent is not accompanied by the liberation of the 

 poisonous group in the protein molecule. This group, 

 probably attached to other groups, or as a constituent of 

 a more complex group, is used in the construction process. 

 The poisonous group is common to all proteins. The syn- 

 thesis of specific proteins from other specific proteins is 

 accomplished without the -liberation of the poisonous 

 portion. It is one of the building stones, and changes in 

 specificity do not occur in this, but in the secondary or 

 characteristic groups. This is, in our opinion, the explana- 

 tion of the fact why incubation a period of rapid repro- 

 duction in the infecting agent proceeds without any 

 recognizable disturbance in the health of the host. The 

 typhoid bacillus therefore does not feed upon the cells of 

 the man's body, but upon the formless, soluble proteins. 

 Cell building is accompanied by the absorption of the 

 poisonous group in the proteins serving as food. However, 

 when the body cells become sensitized and elaborate a 

 ferment which breaks down the bacterial cells, the poisonous 

 group in the proteins of the latter is set free, and it is the 

 effect of this poison that develops the symptom complex 

 of the disease. The symptoms of one infectious disease 

 differ from those of another largely according to the organ 



