278 
ROT IN SHEEP. 
facts with reference to the disease, should name one which posi¬ 
tively contradicts this theory with regard to miasm, and he 
appears to have done so without noticing it at the time. The 
fact to which I allude is this—that on a particular farm there 
was one field in which there was a swamp, hardly to be called 
a pond, and that when the sheep were turned into this field 
during the summer months they became affected with rot. 
This became so obvious to the farmer that after a time he 
hedged in the pond, and prevented the sheep from having 
access to the swampy parts, and then the disease ceased upon 
the farm. Now, this being a fact of which I have very little 
doubt, it at once negatives the idea propounded with regard 
to miasm. If the pond had been thoroughly drained, the 
water being thereby entirely removed, and the character of 
the soil improved, I can understand that miasmatic vapours 
would not have arisen from it; but the pond remaining 
as a pond or swamp, we can of course see that the miasmatic 
matter would arise from it just as much when it was in¬ 
closed with an ordinary fence as when it was open ; and 
this therefore negatives to a considerable extent, if not en¬ 
tirely, the view which Mr. Youatt has taken of this affection. 
Then we have had other individuals who have spoken of im¬ 
pure food as the cause. They say that W’hen there is abund¬ 
ance of moisture, together with an elevated temperature, and 
we have a great growth of grass, especially in damp situa¬ 
tions; that such grass is deficient in nutriment to the sheep; 
that the blood produced from it is impure ; and that hence 
arises a cachectic condition of the body. But this can hardly 
be said to be the origin of the disease, since it would be per¬ 
fectly impossible for impure food or water, or anything else, 
simply as impure material entering into the organism, to call 
into existence the entozoa upon which the disease depends. 
Others, again, have looked to certain plants as the cause of 
the malady ; and there is nothing new even in this. I have 
here a work written by a Mr. Mascall, who was, I believe, the 
chief farrier to King James. It bears the date of 1587, and is 
the original edition. It treats of the maladies of cattle, and 
it has this passage:—“It is good for al men to understand, 
specially shepheards, which things do hurt or rotte sheepe, 
whereby, they maie avoide the danger the better, ye shal 
understand there is a Grasse or weed called Speare Wort, 
the leaves are long and narrow like a speare, hard and 
thick, the steales hollow, growing a foote or more high, 
W 7 ith a yellow floure, which is comonly in wet places, 
and there wil it grow most, or where water have stood in 
the winter. There is also another w r eed called Peniwort 
