OF FOOT-HOT IN SHEEP. 
221 
formed. I know not what quantity of matter was employed, 
neither have we any account of counter-experiments, nor whether 
any were tried to prove whether a similar effect would not have 
been produced by the application of any other morbid matter; 
for example, whether the matter of grease from the heels ol 
horses, or from thrushes, would not have produced similar effects. 
I have little doubt of such being the case,—that suppuration 
might be produced by inoculating w ith that or almost any mat¬ 
ter, if in the operation the w ound was made sufficiently deep; 
nor would I doubt that disease w ould be produced if matter w as 
spread over the foot in sufficient quantity, and applied for a 
sufficient time. 
But I repeat, that it is absurd to suppose that, if applied to 
the hoof, it w r ould produce the disease. The hoof is not go¬ 
verned by the laws of living matter; it is totally insensible, and 
it has not a circulation, neither has it nerves: it absorbs moisture 
only like a piece of inert matter, and it is not acted upon as a 
living part. Matter from the foot of a diseased sheep might as 
well produce the disease in a tree, nay, even more likely, be¬ 
cause it is a living body, which the hoof is not. Why then are 
we to suppose the hoof to be acted upon by matter from diseased 
feet, and that too after the matter has been exposed to the in¬ 
fluence of the atmosphere? But rain and sun, we must suppose, 
have no influence upon it. Arsenic may be diluted with water 
to such an extent as to be swallowed with impunity, but water 
seems to increase the virulence of the matter of foot-rot. It is 
true that heat and moisture will reduce, after sufficient exposure, 
animal matter to a putrid mass of the same consistence and pro¬ 
perties ; but the influence of these agents is lost upon the matter 
of foot-rot. The plague is now known not to be so infectious as 
it was once thought to be, but the foot-rot will still infect the 
most extensive domains. The upas-tree may annihilate the ex¬ 
istence of all that comes within its pestiferous shade; but what 
is that to the infection of the foot-rot, when a single sheep w ill 
contaminate a mountain? Nay, it will act even upon parts 
totally devoid of vitality ; and such, too, is the eccentricity of its 
action, that it will allow its neighbouring toe to escape, and still 
infect the whole ground! 
Was there ever any thing more absurd than the doctrine that 
this disease is infectious ? What is the quantity of matter se¬ 
creted, that it should thus operate; and in what mysterious form 
does it work ? We find but a few drops, even in very bad cases, 
thrown off in many hours ; yet it has been found that it does not 
act upon the hoof, unless the foot has been wounded. Does not 
common sense then declare that infection can have nothing to 
VOL. IV. H ll 
