ON THE VARIOLA OR SMALL-POX OF SHEEP. 631 
loses its efficacy daily. But the period at which it is taken must 
depend upon the fever being perfected, and the pock fully ma- 
turated, taking care in extracting it that it is not mingled with 
blood. 
After the same matter has passed through twelve or fifteen lots 
of sheep it loses its efficacy, and requires to be renewed from 
sheep having the natural pock. This is one great drawback to any 
general systematic course of inoculation as a protection to flocks. 
Matter taken from regular and confluent cases produces equally 
regular and irregular small-pox. Sheep have been inoculated with 
matter taken from those that have laboured under the rot, con- 
sumption, and also the itch, yet it has only begotten the pure 
disease ; nevertheless, it is safer and wiser to take it from healthy 
sheep. 
The desiccated crusts will not give the contagion, nor yet inocu- 
lating with the blood ; but I should have little doubt, if the blood 
of an infected sheep was transfused into a healthy animal, of its 
communicating the disease ; as in a quantity of blood like what 
would be required there would be a full quantum of the virus to 
produce the desired effect. 
In conclusion, strict injunction should be laid upon parties, 1st. 
To carefully keep asunder from the healthy stock, all individuals, 
every description of animals, and even the buckets, utensils, & c. 
that have any connexion with the diseased ones. 2d. Never 
to conduct, or allow to pass, any healthy stock along the fields or 
roads which the diseased ones have traversed, as, from the con- 
tagious matter becoming deposited upon rails, the ground, &c., and 
which preserves its virulence for an indefinite period of time, it 
would immediately give the contagion to others that are healthy. 
3d. As much as possible rear your own stock ; or, at any rate, do 
not purchase fresh stock at either fairs or from parties who traffic 
in sheep, alias sheep-jobbers, but only from those well-known, and 
who can give you a clean bill of health. 4th. Be particularly care- 
ful in folding your diseased sheep sufficiently far away from the 
healthy stock, taking care that the fences are all in good order ; 
keeping them strictly to that portion of your farm ; and also see 
that your neighbours rigidly look after their fences. 5th. Be 
particularly careful not to allow too many sheep to be crowded 
together in your sheds or out-buildings ; as from the intolerable 
stench emitted in this disease, it would be attended with fatal con- 
sequences. I should recommend the infected sheep to be folded 
clean away from the homestead buildings, and temporary sheds 
erected for the worst cases. 6th. Be choice in the food given, 
only giving it in very moderate quantities, or as it is eaten up. 
7th. Ventilate freely the places for the reception of your worst 
