THE BACILLUS OF TETANUS. 395 



and pericardial cavities as well as the blood of tetanic 

 animals would cause tetanus when transferred to other 

 animals. Kahlmeyer, Bruschettini, and others have 

 obtained similar results. The toxin has also been 

 demonstrated in the urine when large amounts have 

 been inoculated. 



Courmont and Doyon believe that the so-called toxin 

 elaborated by the tetanus bacillus is not the true poison, 

 but is a ferment which forms from the poison in the 

 body at the expense of the organism, and is found 

 in the blood, sometimes in the urine, and in, especial 

 abundance in tetanized muscles. The action of tetanus 

 toxin is never suddenly produced, though when once 

 formed its absorption is rapid, but always requires a 

 certain period of incubation. These authors hold that 

 the substances produced by the tetanus bacillus must 

 undergo a chemical change in the body, because after 

 it is formed in the tissues it can be extracted from 

 them by boiling, and when injected into other animals 

 causes immediate tetanic symptoms without any period 

 of incubation. But other observers repeating these 

 experiments have failed to confirm Courmont and 

 Doyon' s results, and appear to have proved their 

 theory to be untenable. 



Tetanus Antitoxin. Behring and Kitasato were the 

 first to show the possibility of immunizing animals 

 against tetanus infection. Here the question of immu- 

 nity against infection does not consist in producing an 

 increased power of resistance against the development 

 of the infecting agent, as is the case in most infectious 

 diseases, but similar to diphtheria, in bringing about 

 an immunity to the effects of the tetanus toxin. The 

 bacillus of tetanus, as we have seen, does not belong 



