398 PRINCIPLES OF VETERINARY SURGERY 



ing, the animals. It was also concluded to attribute the 

 poison to the young virus which produced gangrene by 

 capillary obstruction with microscopic thrombosis. In 

 reality, nothing is more poorly demonstrated; today one is 

 led to believe that the vibrion does not act alone, and that 

 associated micro-organism play a predominant role. It 

 has also been said that the disease is the result of two 

 bacilli ; whereof one causes the septicaemia, while the other 

 produces the gangrene. The fact is, streptococci and var- 

 ious varieties of staphylococci are always found. Besson 

 has shown that the role of associated micro-organism and 

 traumatism has been considerably represented. 



Earth containing the vibrion without being submitted 

 to any special preparation, inoculated under the skin of a 

 cavy, rapidly causes death, but when it is freed of its acces- 

 sory germs by a temperature of 80 degrees C, it does not, 

 under the same conditions, cause a single morbid phenom- 

 enon. The bacteria which are particularly favorable are the 

 staphylococcus, the micrococcus prodigiosus, etc. 



The traumatism has an equally important role, which 

 is well demonstrated by the conditions under which gas- 

 eous gangrene is evolved. The experience of Chauveau on 

 the ram, castrated by torsion of the testicles, and the proof 

 of Besson, confirm the matter from observation. Necrosis 

 of the tissues, fractures, and foreign bodies, by provoking 

 local or diffused destruction of the tissues, are favoring 

 causes of the first order. 



IMMUNIZATION.— Since 1881, Semmer and Visjew- 

 ski have proven that rabbits become refractory to inject- 

 ions of septic blood when they have been previously inocu- 

 lated with the same septic blood exposed for six minutes 

 to a temperature of 55 degrees C. He obtained the same 

 immunity in rabbits with bouillon cultures of septic bac- 

 teria made at a temperature of 35 to 40 degrees C, and then 



