Small-Pox in Sheep. 
551 
sheep, from tin apprehension that they themselves would hecome 
affected. I will not dwell further on this part of the subject, except 
to say that experiments have shown not only that our ordinary 
domesticated animals are insusceptible to the action of the virus, hut 
that it is likewiso the case even with the goat, an animal closely allied 
to the sheep. I have inoculated many goats, and several of them 
three and four times over; I have also kept them among hundreds 
of variolous sheep for weeks together, and yet I have never seen one 
suffer in any way from the affection. 
Origin of the Disease in England. 
I come now to speak of the outhreaks of the disease that havo 
occurred in this country, which is necessary, because some persons 
have thought that small-pox is of spontaneous origin. This view 
was entertained hy many, and especially during the outbreak in 1862 
in Wiltshire, hecause we were not able to trace precisely the manner 
in which the disease was carried there. Persons who hold tho 
opinion that special affections may arise from a combination of 
ordinary causes, laid hold of the fact of the appearance of the 
disease in an isolated part of an isolated county of England, where 
there was little traffic in sheej), as good proof of the spontaneous 
origin of the disease. I may here, however, adopt an expression 
of Dr. Win. Budd, of Clifton, who read an excellent Paper on this 
suhject hefore the meeting of the British Association in August, 
1863, and say, with regard to the spontaneous origin of these diseases, 
that for a thousand years or more we have been endeavouring, in 
every way possihle, to manufacture a special poison ; that is to say, 
we have brought into operation all known causes of disease, and all 
combinations of such causes, not only in animals but in ourselves, 
and we have hitherto failed, with any combination of these causes, 
to produce a single instance of a special poison. We cannot manu- 
facture the poison of the rattlesnake, or a special animal poison of 
any kind or description. Thus you see that all common or ordinary 
causes are perfectly inadequate to account for the introduction or 
appearance of this disease into England. The affection has been 
described most accurately by continental writers from the earliest 
times, and perhaps there is scarcely a part of the Continent where it 
has not frequently existed. Were I to start off now on a mission, 
I believe I should have no difficulty in reaching the disease in 
48 hours in several places, here and there, on the Continent. Yet 
strange to say it has been reserved for the present generation to 
become acquainted with the introduction of the disease into England, 
which was connected with the free importation of foreign sheep. 
The disease was first introduced in 1847 by some sheep which were so 
far the subjects of the malady that the seeds of the disease, — the 
morbific matter, — were lying in a dormant or latent condition in 
their systems at the time. These facts were laid before the public in 
a work which I brought out in the year 1848, in which I traced every 
individual lot of sheep imported ; the vessel which had brought them 
