58 Ths Farmer's Veterinary Adviser. 



V. IMMITNITT BY rSTOOULATION FEOM A CLOSELY BELATED 



DISEASE. 



Tliis was inaugurated by Jenner, who observed that the 

 Gloucestershire milkers who contracted cow-pox never suf- 

 fered from small-pox, and to-day his beneficent method is 

 followed all over the civilized world. 'No two other dis- 

 eases have been yet shown to be vicarious of eaclx other. 



VI. IMMUNITY BY DSTOCULATION WITH A MINIMUM AMOUNT 



OF vmus. 



This consists in diluting the virus in water or saline solu- 

 tion of the density of the blood, until the drop or drops in- 

 oculated contain but one, or at most two germs (bacteria). 

 Dr. Salmon has employed this extensively in chicken-cholera 

 producing a local slongh only, followed by recovery and 

 subsequent immunity from the disease. 



VIL — LIMITATION OF LOCAL DISEASE BY ANTISEPTICS AND 

 CAUSTICS. 



Jenner recognized that an excessive inflammation in the 

 seat of vaccination could be cut short by the caustic appli- 

 cation of the sulphate of zinc or nitrate of silver. In the 

 light of to-day we can recognize in these, antiseptics which 

 destroyed the living germs in the seat of inoculation and 

 prevented their further increase. Similarly, in all those af- 

 fections that are for a time limited to the seat of supei-ficial 

 infection, the general infection may be prevented by the 

 application of caustics or antiseptics to the affected part. 

 This applies to local anthrax, septic poisoning, inoculated 

 lung plague, and even canine madness, and in proportion to 

 the chemical products thrown off into the system before the 

 local disease was arrested will be the measure of protection 

 from a future attack. 



