24 IXOCULATION AS A PREVENTION OF PLEURO-PNEUMONIA. 



Ill the matter of feeding I have not found that any change or 

 special precaution is necessary, provided always the food in 

 quality and condition be non-injurious in itself. 



The necessity for the precautions quoted rests in the circum- 

 stance that the peculiar inflammatory action set up by inocula- 

 tion is apt to localise itself in any part, not the seat of the 

 operation that is inflamed, weakened, or deficient in tone and 

 vigour. And it is curious that, however benign and easily 

 managed inoculation may be, confined to the ordinary seat of 

 operation, it is highly dangerous and frequently fatal if set up in 

 any other part of the body. When I commenced inoculating I 

 was in ignorance of all that I have here cautioned others about ; 

 the path I was treading was a perfectly new one, and it has 

 indeed since often been matter of surprise to me that I did not 

 lose more than I did. 



Mode of Operatimi. 



In proceeding to arrest an outbreak of pleuro, the first thing 

 required is the lymph, or specific virus of the disease, w^ith wdiich 

 to inoculate. This is always attainable in the case of an out- 

 break by simply slaughtering a beast judged to be in the early 

 stages of the disease. Lymph, or virus, is the amber or sherry- 

 coloured liquid exudate found occasionally on the free surfaces 

 of the pleuro, under that membrane, between it and the lung, 

 and nearly always in the interlobular tissues of the lungs ; in 

 consistence it is somewhat viscid, of a not unpleasant odour ; it 

 coagulates readily upon removal from the lungs, but again assumes 

 a liquid condition. In selection of the lympth too much care 

 cannot be taken ; if possible let it be taken from a freshly-killed 

 beast — one in fair condition, and free as far as can be ascertained 

 from other disease, but especially from tuberculosis. My mode 

 of collecting it cannot, I think, be improved upon for simplicity. 

 I open up and pull apart with my fingers the tissues containing 

 it, taking care not to tear or break down their substance ; a pouch 

 is thus formed into which the lymph gravitates, and from which 

 it is spooned out into a clean vessel, a plate or saucer, if for 

 immediate use, or into a clean glass bottle if to be kept, in which 

 case it should be tightly corked up and buried in a few inches of 

 soil until required. The very greatest care must be taken that 

 only lymph as here described be collected, free from all im- 

 purities, blood, frothy serum, and other extraneous matter. 

 Good lymph is only to be obtained in the salmon and brick red- 

 .coloured portions of the diseased lung, never from the hepatised 

 .dark-coloured portions. I mention this particularly, for not only 

 have portions of the hepatised lung been used, but the fluid which 

 follows an incision made through its substance, practices which, in 

 their day, led largely to some of the bad result-s obtained. Lymph 



