SMALL -POX. 351 



the period of writing his work on the sheep "vaccine 

 inoculation is now abandoned on the Continent, although it 

 gives immunity to four-fifths of those that have been subjected 

 to it, for inoculation with le claveau, or the virus of sheep- 

 pox, will give immunity to all." 



"When this malady made its advent in England, it was by 

 imported sheep and the weight of testimony would seem to 

 show that the disease was not apparent in them at the time, 

 but was in its incubatory state. There can be no doubt that 

 the period of incubation is long enough to allow infected 

 sheep to be brought from Europe to America, in the swift- 

 sailing steamers of the present day, before the disease would 

 produce any appearances which those not practically familiar 

 Avith sheep-pox would recognize as characteristic of the 

 malady ; * and the malady might progress much further 

 without its nature being understood or suspected, in any 

 region where it had not been previously known, and where 

 its advent was totally unlocked for. And there is just as 

 little doubt that it might be brought here at any time by 

 wool, or pelts of diseased sheep, or any other substances 

 infected by them, and under some disastrous combination of 

 circumstances introduced, like fire to a train of powder, among 

 the flocks of the American Continent. In England the flocks 

 exposed to its ravages were larger than those of our Eastern 

 States, and much nearer together than those in any part of 

 our country circumstances favorable to its more i-apid 

 propagation there : but there it was encountered with profes- 

 sional veterinary skill cheap labor for attendance and the 

 determined efforts of a government and people which had 

 vast interests at stake, and but a comparatively small home 

 territory to watch over. Here, unless mitigated by climatic 

 circumstances a thing not to be anticipated from any 

 analogy derivable from our experience with small-pox in human 

 beings it would advance more slowly, perhaps, but I 

 apprehend with more destructive results. Our breeders, and 

 the very intelligent and public-spirited breeders of Canada, 

 who are constantly introducing sheep from Europe, are called 

 upon, then, by every consideration of interest and propriety, 



* Prof. J. B. Simond*' Lecturer on Cattle Medicine, etc., at the Royal Veternary 

 College, England, and who was appointed government inspector of diseased sheep, 

 when the sheep-pox appeared in England, states that it is about ten days from the 

 time of the contact of a sound animal with a diseased one before the first symptoms 

 appear. This is to be understood, doubtless, as the average period of incubation, 

 and it might under various circumstances, or in different sheep, be extended several 

 days longer. 



