IMMUNITY AND SUSCEPTIBILITY. 71 



not depending upon the presence of the bacteria, but 

 upon the presence of a poison. 



The antitoxins do not act harmfully upon the bacteria, 

 do not preclude their growth in the animal body, but 

 prevent their pathogenesis by annulling their toxicity 

 i. e. enabling the body-cells to endure the injury and 

 placing them in a position exactly parallel with non- 

 pathogenic bacteria. 



The diseases which are at present controllable by anti- 

 toxins are toxic diseases, caused by the entrance of toxin- 

 producing bacteria into the body. The growth of these 

 toxin-producers probably depends upon the inability of 

 the body-cells or bactericidal body-juices to properly cope 

 with them, so that they develop and engender the poison- 

 ous substances which are the essential factors of disease- 

 production. The more the body and its component ele- 

 ments are injured, the more successful the inroads of the 

 bacteria, the more prolific the toxin-production, and the 

 more severe the affection. 



The presence of the antitoxin annuls the poison, main- 

 tains the vitality of the organism as a whole, sustains 

 the integrity of its tissues, and so places the pathogenic 

 bacterium on a very different footing in relation to the 

 organism. 



An antitoxin is a neutralizing or annulling agent, not 

 a regenerating one, and therefore in therapeutics finds 

 its proper sphere only in the beginning of the disease 

 combated. Up to a certain point the symptoms of diph- 

 theria and tetanus are due to the circulation of toxins in 

 the blood, and can be successfully combated by antitoxic 

 neutralization. Later in both diseases we have symp- 

 toms resulting from disorganization of the nervous sys- 

 tem, degeneration of the heart-muscle, destruction of the 

 kidneys, etc. , and the neutralization of the poison can be 

 of no avail because the lesions are irreparable, and the 

 patient must succumb. 



I have used the term "neutralization," in speaking of 

 the antitoxins, in a rather free and scarcely warranted 



