690 
INAUGURAL ADDRESS. 
is naturalised, so to speak; while in others it has shown itself 
from time to time in wide and disastrous outbreaks. Within 
historic periods the disease has probably at no time appeared 
among healthy flocks unless there had been prior communi¬ 
cation, immediately or remotely, with animals suffering from 
the affection. One sheep will infect a whole ^flock, one 
flock an entire district, and several flocks spread the area of 
infection over a vast country. And so it has happened once 
and again in France, in Germany, and in central Europe. 
But while this communication of sick animals with healthy 
may be said to be an essential element in the propagation 
of smallpox, it is also seen that this cannot be the sole 
element. Now the disease is observed to break out in one 
or two scattered instances, and die away; and anon it prevails 
with a malignity which sets almost all control at defiance. 
At one time, in fact, the flocks show a much higher degree 
of susceptibility to the poison than at another; and this 
consideration has to enter largely into the question of pre¬ 
vention, where, as is the case with our neighbours on the 
continent, the affection is never absent from certain districts. 
I may add that, while in the human smallpox we possess a 
simple, efficacious, and almost altogether harmless means of 
prevention in vaccination, we have no similar unobjectionable 
method in sheep-pox. Vaccination would appear to afford no 
protection to the sheep; and where the separation of affected 
animals proves insufficient to stay the spread of the disease, 
there remains only inoculation to be had recourse to. Nothing 
is more efficacious than this measure for securing the ultimate 
welfare of infected flocks or the interests of the agriculturist 
and the community, where it is rightly adopted and with such 
precautions as its nature requires. Indeed, while we may 
regret that the less formidable disease induced by vacci¬ 
nation has not proved a safeguard in the sheep as in man, 
it is not to be forgotten that the protection yielded by 
inoculation, from being more complete than that which vac¬ 
cination could under any circumstances be expected to give, 
is in this respect more valuable. 
I can well understand that so great an authority as 
Dr. Copland should, on account of the greater protective 
pow r er of inoculation, express something like regret that 
the measure is, in this country, prohibited for man. He 
apparently entertains a doubt of the greater value and even 
fitness of vaccination, as a protection against smallpox. 
On the justness of this doubt I express no opinion; but 
I have thought it well to allude to it at a time when 
the events in Wiltshire have led to much public dis¬ 
cussion of the true worth of inoculation, and when the 
