FOREWORD 11 



mal; also with conspicuous qualitative changes in the direction 

 of the normal. 



(5) Physiological changes, including rises of temperature, 

 quickened pulse, and a chill are not infrequently associated with 

 the administration of the remedies in question, suggesting an 

 anaphylactic reaction, not known to be produced by anything 

 but protein or its products. This reaction appears not to be 

 evoked in the same degree by partially hydrolyzed proteins. 



(6) It has been observed that a condition of immunization 

 appears to be attained sooner or later, after which the patient 

 no longer responds in the same way to a particular protein; 

 but that change to another protein may bring about a new re- 

 sponse, with possibilities of cumulative beneficial effects. 



The theories on which these observed facts are explained by 

 the present writer are the following: 



(1) The essential point of contact between the different sub- 

 stances administered hypodermically is their protein content 

 (either the full molecule or products of partial hydrolysis). 



(2) Any foreign protein injected into the parenteral system 

 serves as an antigen and stimulates the defensive mechanism of 

 the body to the production of antibodies capable of hydrolyzing 

 foreign proteins of various types. 



(3) Such antibodies are enzymic in character, and both specific 

 and general in nature that is to say, they hydrolyze the par- 

 ticular protein injected, but also other foreign proteins if present. 



(4) The proteins of cancer are in a sense foreign proteins and 

 fall within the scope of action of the enzymes called forth by 

 the medical protein antigens. The degenerative diseases of 

 middle life and old age are usually associated with disturbances 

 of metabolism involving the parenteral invasion of foreign pro- 

 teins or the undue retention or incomplete catabolism of protein 

 end products. Tuberculosis falls within the same category be- 

 cause of associated secondary infections and the accumulation of 

 localized foci of autologous and bacterial proteins subject to 

 hydrolysis by the corpuscular enzymes. 



(5) The mechanism particularly involved in the production of 

 the protein-hydrolyzing enzymes is the blood-forming mechanism 

 and its products, the white and red corpuscles. 



(6) The general province of the white corpuscles is to deal 

 with the full-sized protein molecule or its early cleavage prod- 

 ucts, and the province of the red corpuscles is to deal with the 

 end products of polypeptid order, including bodies of the hypo- 

 zanthin-zanthin-uric acid-urea series. 



(7) The condition of the abnormal hyperplasia of the cells 

 of various organs of the body, including the blood-forming or- 

 gans, the coats of the arteries, and the cells of epithelial, endo- 



