220 MR. DICK ON THE CAUSES AND PREVENTION 
tity of grass upon it, are prevented from being worn down, the 
disease will be found to prevail; and in those situations where 
the soil is rich and moist it will be found more particularly in¬ 
creased. For similar reasons, it will prevail more especially 
where there is a superabundance of grass; and on dry old pas¬ 
ture it will be found to proceed most rapidly at t!\e season when 
the dews are greatest. When it occurs on light sandy soils, the 
dry seasons will be most liable to produce it. 
All this, it will perhaps be said, may be quite true, and still 
* the disease has not been divested of its contagion. One will 
say he knows of ground where foot-rot never existed before, be¬ 
coming infected by a few sheep, perhaps a single one, having 
been brought upon it, and that the disease has spread in a few 
weeks to the whole flock. Another will say he knows of a case 
where all the ewes of a flock have caught the infection from a 
single ram. But, in such cases, has nothing been done in the 
way of improving these lands? The Ettrick Shepherd, in a 
paper in the last Number of the Quarterly Journal, has shewn that 
even the alterations produced by the destruction of moles has 
a material influence in causing it, and that, too, while he at the 
same time considers it infectious. But has any one ever attempted 
to produce the disease by inoculation ? If it is highly infectious, 
surely it will at once be produced by inoculation. But this is not 
such an easy matter as one would expect from a disease which is 
supposed to infect a whole field, and that, too, even if it be of 
five hundred acres in extent. 
Gohier, a French veterinarian, first applied a piece of horn 
from a diseased foot, covered with the matter, to the sole of a 
sound foot, without effect. Secondly, he rubbed a diseased foot 
against a sound one, without effect. Thirdly, he pared the sound 
foot, and having applied a piece of diseased hoof, the disease 
afterwards appeared; but, in this case, the foot afterwards got 
well of itself, and there seems to have been a doubt in the mind 
of Gohier as to whether it was truly foot-rot or not. 
Other French veterinarians have tried similar experiments, 
and particularly Vielhan of Tulle, and Favre of Geneva; and 
although I have not seen an account of their experiments, it is 
said they succeeded in producing the disease by inoculation. 
Now, it will be asked, is not this a sufficient proof of its infec¬ 
tious nature ? I answer that it is not. It appears to me that 
this is a strong proof against it. If it is produced with so much 
difficulty by the direct application of matter, is it not absurd to 
suppose that a few sheep with diseased feet should infect a 
whole field ? I have not seen an account of the manner in 
which the experiments of the French veterinarians have been per- 
