244 PATHOGENIC BACTERIA. 



As the incubation-period comes to an end there is an 

 observable alteration in the wound, which becomes red- 

 dened, sometimes may suppurate a little, and is painful. 

 The victim, if a man, is much alarmed and has a sensa- 

 tion of horrible dread. The period of dread passes into 

 one of excitement, which in many cases amounts to a 

 wild delirium and ends in a final stage of convulsion and 

 palsy. The convulsions are tonic, rarely clonic, and 

 subsequently cause death by interfering with the respira- 

 tion, as do those of tetanus and strychnia. 



During the convulsive period much difficulty is experi- 

 enced in swallowing liquids, and it is supposed that the 

 popular term "hydrophobia" arose from the reluctance 

 of the diseased to take water because of the inconveni- 

 ence and occasional spasms which the attempt causes. 



This description, brief and imperfect as it is, will 

 illustrate the parallelism existing between hydrophobia 

 and tetanus. In the latter we observe the entrance of 

 infectious material through a wound, which, like the 

 bite in hydrophobia, sometimes heals, but often suppu- 

 rates a little. We see in both affections an incubation- 

 period of varying duration, though in hydrophobia it is 

 much longer than in tetanus, and convulsions of tonic 

 character causing death by asphyxia. 



It is maintained by some that the stage of excitement 

 argues against the specific nature of the disease, but 

 these subjective symptoms are like the mental con- 

 dition of tuberculosis, which leads the patient to make a 

 hopeful prognosis of his case, and the mental condition 

 of anthrax, in which it is stated that no matter how dan- 

 gerous his condition the patient is seldom much alarmed 

 about it. 



Pasteur and his co-workers found that in animals that 

 die of rabies the salivary glands, the pancreas, and the 

 nervous system contain the infection, and are more 

 appropriate for experimental purposes than the saliva, 

 which is invariably contaminated with accidental patho- 

 genic bacteria. 



