450 PRINCIPLES OF VETERINARY SURGERY 



mals. In the cold-blooded animal, the frog, turtle, etc., no 

 neutralizing action occurs. These writers have demon- 

 strated in opposition to Wasserman, that the nerve sub- 

 stance is neither vaccinating nor curative. Other substances, 

 nervine, and hydrochlorate of betaine also neutralize the 

 toxin. By basing conclusions on these experiments it has 

 been supposed that the toxin localizes in the nerve cells of the 

 brain and causes alterations which are responsible for the 

 tetanic spasms. But in reality the toxin does not combine 

 with the nerve-cell protoplasm. It is simply fixed, and the 

 fixation is not permanent. If an emulsion of brain charged 

 with toxins is macerated it will dififuse through the men- 

 struum, and will prove to be active in proportion to the 

 amount of toxin contained. The experiment of Wasserman 

 is therefore artificial and insufficient to explain the develop- 

 ment of tetanus. There is nothing to prove the affinity of 

 nerve protoplasm, so clear in vitro and also recognized in 

 vivo. The diffusion of the toxin is not regular. As has been 

 already shown animals may remain tetanic when their nerv- 

 ous systems no longer contain toxins. In order to clearly 

 demonstrate the affinity of the cerebral cells to tetanic toxin, 

 Roux and Borrel have produced "cerebral tetanus." They 

 injected tetanus toxin directly into the cerebral substance 

 of the rabbit, the cavy and the rat, and thus obtained a local- 

 ized disease of the brain, characterized by symptoms of cere- 

 bral origin : — hallucinations, epileptic crises and cerebral ex- 

 citement, without medullary symptoms or spasms. In the 

 rat, the phenomena were most startling. It became mad 

 and the victim of hallucinations. The poison was immediate- 

 ly fixed by the brain and was not diffused as far as the spinal 

 cord. It seems then, that the cerebral cells fix the tnxin in 

 the living animal as well as in the crucible, — "in vivo as in 

 vitro." Courmont and Doyon have endeavored to prove 

 that fixation has really occurred. The fact that the toxin 



