16 INOCULATION AS A PREVENTION OF PLEURO-PNEUMONIA. 



become a contagious centre, capable of disseminating the disease, 

 C[uite as much as an ordinarily affected one. I believe myself 

 correct in affirming, that this fact, which is really one of the 

 most important in connection with our subject, is not generally 

 known. In a paper like this, however, the matter must be 

 placed beyond all doubt, and I am glad to be able to do so, not 

 only from my own experience, but by the testimony of those 

 who have made inoculation the subject of their investigation. 



Dr. Willems of Hasselt in Belgium, who was the first to be 

 successful with the operation, thus puts it : — " By inoculating 

 pleuro-pneumonia a new disease is produced, the affection of 

 the lungs, with all its peculiar characters being localised on some 

 part of the exterior," vich Williams' Veterinary Medicine, p. 152, 

 and again on page 153 of the same volume, we find the Belgian 

 commission arrived at the conclusion, that the " Inoculation of 

 the liquid extracted from the lungs of an animal affected with 

 pleuro-pneumonia does not transmit to healthy animals of the 

 same species, the same disease — at all events so far as its seat is 

 concerned." 



During my visits to Australia, I learned from Mr. Graham 

 Mitchell, r.PuC.V.S., and from Mr. Alexander Bruce, chief 

 inspector of stock for New South Wales, both of whom have had 

 a long and extensive experience of inoculation, that their obser- 

 vations had led them conclusively to the same opinion. 



Better than all, however, is the evidence wdiich 1 can offer 

 myself. During the last two or three years I have effectively 

 inoculated between 2000 and 3000 head of cattle, milkers 

 chiefly, of which number at least 2500 have since been 

 slaughtered for public consumption. Most of them have been 

 killed at the abattoirs of Edinburgh and Leith, and have always 

 been found to have perfectly unaffected healthy lungs, so far at 

 least as pleuro has been concerned. I do not in the whole course 

 of my experience know of a single instance to the contrary, and 

 have no hesitation in saying it may be taken as a well-ascer- 

 tained fact, that " An inoculated animal, healthy at the time of 

 operation, cannot possibly communicate pleuro-pneumonia to 

 another one." I have frequently been asked the question, 

 " Will an inoculated animal contract pleuro-pneumonia ? " To 

 such question as the result of my experience I can with confi- 

 dence reply, No. I do not know of a single instance of such, but 

 I would draw attention to the fact that I emphasise the word 

 inoculated. In unskilful or careless hands, or from other cause?, 

 an animal may have been put through the form of the operation 

 and still not have been inoculated, such a one may undoubtedly 

 contract the disease ; but I say that no animal will contract it 

 that, after having been operated upon, has exhibited the charac- 

 teristic features of inoculation, in proof of which I can give 

 innumerable instances. 



