EPITOME OF EVIDENCE ON PLEURO-PNEUMONIA. 263 



one that gives immunity to an animal from pleuro-pneumonia 

 during the rest of its life if it succeeds in taking on the inocu- 

 lation, but I would say for two years. I would put a term to 

 the immunity without further experience. I think it a good 

 thing for the Society to consider this as part of the inquiry. Prac- 

 tically, it gives immunity during the ordinary life of a feeding 

 beast. Anybody could inoculate. I think it could be entrusted 

 to the hands of an ordinary veterinary surgeon. The only thing 

 is the selection of the lymph ; it is a difficult thing to select the 

 lymph. It is a thing to which j^ou would require to train the 

 veterinary surgeon, otherwise the process would break down. 

 After a man has seen the lymph containing the virus, there is 

 no chance of his mistaking it thereafter. It is my opinion that 

 the best way to treat an outbreak of jDleuro-pneumonia is to 

 slaughter everything that is suspicious, and inoculate all the 

 rest. There are certain stages of this pleuro-pneumonia disease 

 in which it is impossible for the most skilled expert to detect 

 the disease in the animal at first, but that is not a common 

 thing. As to how long it would be impossible for one to 

 detect the disease, given pleuro-pneumonia in a herd, any 

 deviation from the normal health in any single individual 

 animal would be sufficient to show that the disease was latent 

 there. I would treat it as disease even in the absence of positive 

 symptoms; professional skill enables one to detect it. It is only 

 one in a hundred that I would fail in, I include in that the fact 

 that the cow has not been able to take on inoculation. If it did not 

 take the inoculation within fifteen days or three weeks, I should 

 say it was a suspicious case. An animal with pleuro-pneumonia 

 in the initial stage will sometimes take inoculation, and will 

 have both the inoculation lesion and the pleuro-pneumonia 

 lesion, but it is very rarely the case. I have had actual 

 experience of that from my own observation. I have found 

 that an animal had all the symptoms of a thoroughly well- 

 made-out case of pleuro-pneumonia, and yet it took on inocula- 

 tion. There are few cases of that kind. I have seen two such 

 cases within the first three weeks after inoculation. I think 

 it is as perfect as vaccination in the human being. Then, when 

 an animal does not take on inoculation, in the event of there 

 being an outbreak, I would regard it as tainted — as having had 

 the disease ; I would slaughter that animal. I should not 

 prescribe inoculation for a healthy herd. If they were only 

 within 300 yards of the disease, I do not think I would do 

 it ; unless the disease was in the byre, I would not do it. 

 I have done it to please people — to satisfy clients. It is the 

 same as in vaccination ; you cannot account for its failure. I 

 am of opinion that in inoculating animals there are uncertain 

 circumstances, when you have to depend on the exudate of a 



