SMALL-POX IN SHEEP. 
467 
that which is of a benign description, and has been deprived of its 
acridity ( affaibli ) by several successive transmissions, and that 
has been taken at a time when inflammatory phenomena have for 
the most part left the pustule, or, in other words, about the tenth 
or twelfth day from that of inoculation ; of making no more than 
one puncture in the tail, and so endeavouring, as much as possible, 
to introduce but a feeble dose of the virus into the orgasm : with 
precautions such as these, now that it is ascertained by veteri- 
narians that the sheep-pox virus retains its active properties for a 
period from fifteen to eighteen months, what ought one not to hope 
from well-conducted inoculations ] 
I believe, therefore, we are at liberty, at this day, to conclude 
that the inoculation of flocks of sheep already suffering from small- 
pox, either in a sporadic, enzootic, or epizootic and fatal form, the 
same as inoculation of flocks in good health, but threatened with 
contagion, is an operation which, up to the present time, has been 
followed by unquestionable success; and one which, in our day, 
cannot be viewed in any other light than as being highly advan- 
tageous to the conservation of our flocks, seeing it reduces their 
losses from 15 to 20 per cent, at least, in the case of natural pox, 
down to 1 or at most 2 per cent. 
I ought not to omit to add, that the inoculated small-pox of our 
day, being a disease of a more benignant character, rarely or never 
is productive of those incurable infirmities or those serious conse- 
cutive maladies which happen after natural and epizootic pox ; and 
especially ought I to remark, that such inoculations as are made 
with benign virus are but very rarely followed by secondary 
eruptions, and that, consequently, the fleece of the sheep under- 
goes, in general, but slight alteration, an advantage which will not 
fail to be highly appreciable by farmers, and by those in particular 
possessing flocks whose wool is precious. 
15. When natural small-pox breaks out in a flock, its ordinary 
duration is from three to four months ; whereas the inoculated 
disease in a whole flock will not occupy more time than a single 
attack, or at most one month. 
16. There is no reason to doubt for a single moment that inocu- 
lation is preservative during the entire life of the animal against 
small-pox. A computation made by D’Arboval shews that 7697 
inoculated sheep have been either submitted to divers counter- 
proofs of inoculation, and that these have been variously repeated ; 
or have been made to cohabit with sheep suffering from the natural 
pox , and that in no case has any disease been contracted. 
17. In the case of natural and malignant pox, the loss of a 
fourth or a third of the animals of the flock, although grievous 
enough for the farmer, is still not his entire loss. The numerous 
