POISONS AND THEIR PREVENTION 211 



only on taking this step that he succeeded in in- 

 variably provoking rabies in the animals under 

 experiment. 



In the case of tetanus we have another disease 

 affecting the nerve-centres of the body, and al- 

 though many authentic cases have been cited in 

 which the treatment with anti-tetanic serum has 

 been entirely successful, a great many instances 

 have occurred in which it has been of no avail 

 at all, more especially when the disease has 

 obtained a firm hold on its victim. Now Dr. 

 Roux has not only been carrying out experi- 

 ments to ascertain what is the result of directly 

 attacking, as Pasteur did in the case of rabies, 

 the nerve-centres of an animal with the tetanus 

 toxin, but he has also taken another and very 

 important step further, and has investigated, not 

 only the action of the toxin, but also that of the 

 anti-toxin on the nerve-centres of an animal 

 suffering from tetanus. 



In describing the cerebral inoculations which he 

 has conducted on animals, Dr. Roux points out 

 that the operation, in itself, is attended with no 

 pain or even inconvenience to the animal in 

 question, that subsequently it eats with its usual 

 appetite, and shows no signs of discomfort. 



First, as regards the infection of an animal with 

 the tetanus virus introduced directly into the brain, 



