430 PROTEIN POISONS 



six hours and would be followed by from twenty-four to 

 forty-eight hours of extreme exhaustion. At no time has 

 such a reaction been obtained, even with doses of 10 c.c., 

 when given subcutaneously or intravenously away from the 

 tumor; although a chill from one to three hours after injec- 

 tion has been observed. We wish now, however, to call 

 attention only to the animal experiments, the above being 

 mentioned simply because it is additional proof of the 

 presence of a specific ferment. 



It is of interest to note here also that a vaccine prepared 

 from human carcinoma gives a much higher percentage of 

 large mononuclear leukocytes when injected into a rabbit 

 or sheep than when injected into a human being. This 

 has been observed regardless of whether the human being 

 had malignant disease or not. I have injected cancer 

 vaccine into myself, and the highest resulting percentage 

 of large mononuclear leukocytes was 15. This fact is of 

 interest when we consider that with experimental cancer 

 the animal injected must always be of the same family as 

 the one that furnishes the tumor in order to obtain a 

 "take." 



It should not be understood that we consider the ferment 

 causing reproduction in the cancer cell to be of exactly the 

 same chemical nature as the active ferment of a reproducing 

 normal cell, but rather that we are dealing with a chemically 

 altered constructive ferment, a fact that we will demon- 

 strate later. 



While attempting to use leukocyte extract from animals 

 sensitized to the cancer protein in a therapeutic way, it 

 was found that extract prepared by filtering through a hard 

 filter paper would upon repeated usage in the same case 

 cause symptoms of sensitization; while the use of extract 

 prepared by Berkefeld filtration would not be followed by 

 these characteristic phenomena. At the same time, as 

 previously mentioned, all of the specific ferment passes 

 with ease through the filter. 



In order to ascertain what constituents were removed 

 from the leukocyte extract by passage through the Berkefeld 



