G2 RINDERPEST. 



to specific disease, 2JoisonSy capable of propagation from one 

 animal to another, and communicahle either by direct contact 

 or indirectly through various channels of intercourse.* 



It is frankly admitted that this or any classification would 

 be valueless in the investigation of the Einderpest, unless it 

 be conceded that this epizootic is wholly distinct from others, 

 not only in its leading characteristics, but in its source or 

 origin as a blood-poison. And it is principally in this latter 

 sense, that we can pronounce it a disease " sui generis,'^ 

 developed through the agency of a poisonous germ, which 

 breeds after its own type, and multiplies "after its own kind," 

 and by a process as regular and uniform as that (to use the 

 emphatic though homely language of John Simon, medical 

 officer of the Privy Council in his sixth report) " by which 

 dog breeds dog, and cat breeds cat, and as exclusive as that 

 by which dog never breeds cat, nor cat dog." 



The seminal principle or germ of the Pest being considered 

 then as one and distinct from that of other epizootics, its vary- 

 ing manifestations remain to be accounted for. Its develop- 

 ment as to time and potency is dependent upon certain 

 spheric conditions, and the different susceptibility of races 

 and individuals. Prof. Roll states that for many years the 

 cattle plague hung upon the Polish frontier without entering 

 Austria, until certain other diseases appeared among cattle 

 and men, and then it became a general pestilence. As far as 

 the historical records of other desolations among the lower 

 orders of creation bear reliable testimony, this view is corro- 

 borated. It is also confirmed by the cyclical jjeriods which, 

 as is claimed, mark the devastation of this plague in its 

 native steppes. 



Again, it has been too frequently observed to admit of 

 denial, that its fatality has been less marked with those cattle, 

 of whom it may be said that the Pest is to their manor born, 

 than among other races. Devons taken to Russia, after thriv- 

 ing admirably for a time, when brought within range of this 

 distemper, yielded under its most frightful manifestations, 

 and in droves. 



* See Aitken'B Science of Medicine, Vol. 1, p. 900. 



