Inoculation for Pleuro-Pneumonia in Cattle. 377 



tlie manner of performing- the operation. It remains, however, to 

 be proved that, even with the greatest care, the casualties may not 

 be so numerous as to offer a serious drawback to the adoption of 

 inoculation, if it should hereafter be satisfactorily shown to be a 

 preventive of pleuro-pneumonia. 



Deputations have been sent bj France and Holland, and also 

 by the Belgian Government, to Hasselt, to inquire into the value 

 of the practice, but up to the time of my visit Prussia had not 

 taken this step, nor had Dr. Willems been requested to under- 

 take any inoculations in that country. This delay may possibly 

 have arisen from the ill consequences of Dr. De Salve's opera- 

 tions producing a want of confidence on the part of the Govern- 

 ment of Prussia. From a letter which I have recently received 

 from Dr. Willems, it appears that experiments are being carried 

 out both in France and Holland at their respective veterinary 

 schools, and also that Prussia is about to follow the example 

 of these countries. 



The Government of Belgium is taking the liveliest interest 

 in the matter, and has instituted a series of valuable experi- 

 ments, so that ere long it will be satisfactorily proved whether 

 inoculation is or is not a certain and safe preventive of the dis- 

 ease. It is a fact long since established in medicine that many 

 contagious diseases can be readily communicated from animal ta 

 animal by inoculation, thereby giving immunity from an attack of 

 the "natural" disease. The "inoculated" disease also, as a rule,, 

 proves of a less dangerous character than the natural, but it is 

 especially to be remembered that in their nature both are essen- 

 tially the same. The advocates, however, of the inoculation of 

 cattle build the success and value of their practice on the very 

 opposite basis, because they say in no case is disease of the 

 lungs caused by the introduction of the morbific matter into the 

 system. Were disease of the lungs to follow, it would be at once 

 fatal to the practice, because its effects being made manifest within 

 these organs could not be controlled, and would assuredly lead on 

 to death. The local disease caused by the inoculation, we are told, 

 is of the same nature as that in the lungs of affected cattle ; but is 

 said always to remain localized, because artificially introduced into 

 the organism. About two per cent, of the inoculated animals die, 

 while a far greater proportion suffer from ulcerative and gangrenous 

 inflammation of their tails, notwithstanding which the lungs, the 

 locale of the natural disease, we are assured, never suffer. If ex- 

 perience proves this to be true, it must be regarded as a new fact 

 in medicine. 



We believe each virus, no matter how introduced, naturally or 

 artificially, into the system, to have its own especial seat in the 

 organism. Thus the virus of glanders produces glanders, and 



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