550 Abstract. Report of Agricultural Discussions. 
that the disease is not positively identical with that which is so 
called in the human subject. There can, however, be no difference 
of opinion between medical men as to the intimate analogy which exists 
between the two affections ; and it may be said that they are as closely 
allied as it is possible for any two diseases to be that affect animals 
of different species. Indeed, it has been rightly observed that they 
agree as much as any two mushrooms of different species, or any 
two alga3, or vegetables of other low class, may be said to do. Such 
being the case, the propriety of the term that has been given to this 
affection cannot be questioned, although the term itself may have led 
to some incorrect conclusions on the part of individuals, e. {/., that the 
disease having had a prior existence in the human subject, had spread 
through ordinary infection from man to the sheep ; or that having had 
its origin in the sheep, it was liable to extend from the sheep to the 
human subject. Both these views are erroneous. The outbreaks of 
sheep-pox in this country can in no way be traced to disease of 
prior existence in the human subject, and its communication by man 
to the sheep ; nor can we say that the disease, having appeared in the 
sheep, has spread to the human subject. Speaking in general terms, 
and bearing iu mind that these diseases are of distinct species, although 
so closely allied, I think we may say that the small-pox of sheep, 
so far as we are acquainted with it, is an affection which belongs 
exclusively to the sheep, and has not yet been proved to be cajiable 
of being communicated to either the human subject, or any domes- 
ticated or even wild animal. Experiments on a very large scale have 
been instituted, and these have been invariably attended with nega- 
tive results. In the year 18-48, when the affection was exceedingly rife 
among sheep, acting in conjunction with Mr. Marson, Surgeon to the 
Small-Pox Hospital (who is considered to be one of the highest autho- 
rities in variolous diseases in this country), and Mr. Cceley, of Ayles- 
bury (who has devoted almost his whole life to affections of this 
description, and is employed by the Government to sec that the vac- 
cine matter supplied to the hospitals is obtained from proper sources), 
I inoculated several children with the virus of sheep-pox, and, in every 
instance, we failed to produce any special disease. Abortive vesicles 
rose on the arm in some cases, but came to nothing. I may further 
say, that, in inoculating sheep, as I have done now on rather 
a large scale, it has not unfrequcntly happened that, owing to the 
sheep plunging about, the needle charged with the virus has 
entered my finger, and I have thus accidentally inoculated myself 
probably not less than from 15 to 20 times, yet I have never ex- 
perienced the least possible inconvenience. It has*' also happened 
that in the same accidental manner I have inoculated shepherds 
and men who were assisting me in performing the operation. In 
these individuals, too, there has always been a negative result. 
It is well that one can speak in this positive manner, because 
a notion has been entertained by labourers and other uneducated 
men concerned with sheep, that they and their families arc likely 
to contract this variolous disease, and some of them have almost 
hesitated to assist me either in the examination ot inoculation of 
