INOCULATION AS A PREVENTION OF PLEURO-PNEUMONIA. 25 



may be kept in cold weather fit for use, if excluded from the air 

 for from three to five days, but in warm weather it cannot well 

 be kept quite fib for use beyond the second or third day. There 

 are ways of preserving it for two or three months ; but, as my 

 experiences have been rather unfavourable to using 13'mph in 

 any way but in its pure state, I do not mention them, since I 

 cannot recommend their adoption. In my hands, as in those of 

 others, the use of preserved lymph, which is frequently weakened 

 or in some way changed, has been attended with uncertain 

 results ; as, however, in inoculating we wish to have perfect 

 exemption, I long ago gave up its use. 



Having obtained the lymph, the operator next procures fully 

 as many pieces of white Alloa worsted, eight inches long or so, 

 as there are cattle to inoculate. These threads he saturates with 

 the lymph ready for use, the threads in the meantime being the 

 means of retaining the virus until insertion beneath the skin of 

 the animal, aft-er which, from their presence there, they help to 

 localise the inoculative action. 



In the actual performance of the operation various methods 

 have been adopted. Most of them, however, are open to grave 

 objections, not only as regards the material employed, but in the 

 spot selected and manner of doing it. I have to condemn as 

 dangerous the practice of making deep and cruel incisions in the 

 head of the tail and of inserting therein pieces of diseased lung ; 

 as also the modes recommended and carried out lately at the 

 Brown Institution in London by Dr. Burdon Sanderson, viz., by 

 subcutaneous and intravenous injection of the virus. Both are 

 in their nature unreliable, and the latter is in my opinion not 

 only a mode fraught with danger to the lives of the animals, but 

 with the great bulk of them, and in most hands impracticable. 

 Others again, in imitation of vaccination, merely scratch or 

 scarify or incise the skin of the tail, and rub in a little virus. 

 This mode is not attended with danger, but in my experience 

 many of such so-called inoculations fail from being incomplete 

 nnd too mild. The mode adopted by myself, and I think my 

 results have proved it a good plan, is the insertion at the tip of 

 the tail of a woollen thread saturated with the virus or lymph in 

 a manner similar to the insertion of a small seton. The advan- 

 tages claimed are — 



1. The minimum of danger, as a result of the inoculative 



action, spreading from the seat of operation. 



2. In the event of the inocidation spreading it can be arrested 



by amputation, which cannot be done in any other ])art 

 of the body. 



3. The o})eration is simple and easily performed. 



The instruments required are a pair of strong scissors, a pair 

 of rowL'lUng scissors and a needle, which latter has to be made 

 specially for tlie purpose. The one I use is provided with a 



