256 THE INVISIBLE WORLD 



But the bite of the mad dog is bad enough. As 

 the disease develops, it sets on fire the brain, and 

 throws into convulsions the whole nervous system. 

 It needs no description. 



What do? The moment one is bitten, call the 

 up-to-date surgeon. He will cauterize the wound. 

 This will prolong the period of incubation, and 

 thus give more time for treatment, He will then 

 take the patient to the nearest Pasteur Institute. 



The patient here will receive the Pasteur treat- 

 ment. If he arrives in season, the treatment will 

 surely cure. 



The surgeon in charge has on hand mad dog 

 virus attenuated a la mode Pasteur, weakened 

 successively, degree by degree, by passing it 

 through a series of monkeys, till the weakest de- 

 gree will not kill. 



As soon as the patient arrives at the Institute, 

 the surgeon inoculates him with virus at weakest 

 degree. The body cells of the patient set up in his 

 system antitoxine which counteracts the virus. 



On the second clay, the surgeon inoculates the 

 patient with the next stronger degree of virus. 

 The body cells of the patient continue to set up 

 antitoxine which, counteracts this virus. 



The third day, the surgeon vaccinates his patient 

 with the next stronger degree of virus. By con- 

 tinuing their work of setting up antitoxine, the 

 body cells prepare the patient to resist this third 

 degree. 



This process is continued until the patient is 



