112 BACTERIOLOGY 



injections are made. To be of value the immunizing 

 process must be given before the onset of the disease, as 

 soon as possible following the bite of the rabid animal. 

 As the incubation period of hydrophobia is long, extend- 

 ing from three weeks to several years, sufficient time is 

 usually available for treatment. 



Recently, enterprising manufacturers have succeeded 

 in perfecting a plan whereby they furnish the vaccine 

 for the entire treatment of a case upon telegraphic 

 notice, shipping the varying strengths in a Caloris bottle, 

 which protects it from changes of temperature. The 

 physician is thus enabled to give the treatment at the 

 patient's home, saving tune and the necessity of a 

 long journey to some distant institute. 



It should be remembered that this is a purely prophy- 

 lactic measure, the organism being rendered immune to 

 the disease during the period of incubation, and that 

 after the onset of the symptoms the treatment is useless. 

 No time should, therefore, be lost following a bite by a 

 suspected animal in beginning treatment, either at 

 the nearest Pasteur institute or by means of the vaccine 

 prepared and forwarded to the physician by the dealer 

 in serums and antitoxins. 



Mode of Action. While it is impossible to say with 

 certainty just how immunity is established by this treat- 

 ment, it is, without doubt, analogous to small-pox 

 vaccination. 



A modified form of the disease is produced by injec- 



