PROTEIN FEVER 405 



Man is immune to most bacteria, not because they do not 

 elaborate poisons, for every protein molecule contains its 

 poisonous group, but because they are destroyed by the 

 general proteolytic enzymes as soon as they enter the 

 tissue and consequently are not permitted to multiply 

 in man's body. These non-specific, parenteral proteolytic 

 enzymes are probably secretions of certain specialized 

 cells. Under natural conditions these enzymes are capable 

 of digesting those proteins upon which they do act only in 

 small amounts, but the cells which elaborate them may 

 be stimulated to increased activity by proper treatment, 

 and the method detailed in this paper seems to accomplish 

 this purpose. Whether or not these enzymes become 

 qualitatively specific under such treatment as we have 

 detailed can be determined only by further study. The 

 immunity secured by these enzymes is limited in extent 

 and transitory in duration. 



The specific, parenteral proteolytic ferments are not 

 normal products of the body cells, but are brought into 

 existence under the stimulation of those proteins, intro- 

 duced into the blood and tissues, which on account of their 

 nature or amount escape the action of the non-specific 

 ferments. It is to the development of these ferments that 

 the phenomena of sensitization (wrongly called anaphyl- 

 axis) are due. A protein introduced into the blood and 

 not promptly and fully digested by the non-specific enzymes 

 is discharged from the blood current and deposited in some 

 tissue, the cells of which after a time develop a specific 

 ferment which splits up this protein and is not capable of 

 acting upon any other. For certain proteins there are 

 certain predilection organs and tissues in which they are 

 stored, either exclusively or most abundantly: the pneu- 

 mococcus in the lungs; the typhoid bacillus in the mesen- 

 teric and other glands; the viruses of the exanthematous 

 diseases in the skin, etc. For the development of the specific 

 proteolytic ferments time is required, and this varies with 

 the protein and probably with the tissue in which it is 

 deposited. The development of these ferments necessitates 



