PRINCIPLES OF VETERINARY SURGERY 437 



the bacillus of Friedlander do not exert any favoring in- 

 fluence. All of these details apply exactly to the pns co'- 

 lected from the wound of a tetanic man or animal that has 

 died from the inoculation of earth. Deposited under the 

 skin of a cavy this pus rapidly produced fatal tetanus. But 

 after heating ten to fifteen minutes at 68 to 70 degrees C. 

 it becomes inactive, even with a double dose. Here, again, 

 it is easy to establish what is the indispensable element 

 in the pathogenesis of tetanus, which heat caused to dis- 

 appear. It is not the specific bacillus ;_the cultivation of a 

 quantity of this pus not heated, equal to that which has been 

 inoculated, gives a very toxic culture. It is the bacteria 

 that vegetate with it that have been eliminated, and which 

 thrive in the tetanic wound of both man and animals. If, 

 by cultures in gelatin, in the air, and in a vacuum, attempt 

 is made to determine the quantity of other microbes con- 

 tained in this pus, before and after heating, striking results 

 are obtained. The quantity sown remaining identical, the 

 pus before heating always gives a conside,rable number of 

 various micro-organisms. After heating only colonies of 

 tetanus bacilli are formed. The heated pus contains only 

 the tetanus bacillus that is not virulent and does not 

 cause local lesions. The pus that is not heated is tetanigenic. 

 Besides the tetanus bacillus it contains a number of diiTer- 

 ent micro-oi'ganisms. It is because the latter have disap- 

 peared that the heated pus does not cause local lesions, 

 and that in consequence of the fact that the' specific germs 



cannot grow. 



ANNOTATION. 



The following, then, is the summary concerning the action of B. tetani 

 and its terms as confirmed by the foregoing experiments : — 



1. B. Tetani is the specific cayse of tetanus. 



2. Other bacteria, such as B. prodigiosus, are indispensable to the germ- 

 ination and growth of the tetanus bacillus. 



3. The toxin acts in special thermic conditions and always in every 

 animal after a period of incubation, which does not vary as to the dose 

 given. 



