458 
A. LIAUTARD. 
resist the injuring action of external agents ; suppleness in its deep 
layers, to establish a transition and avoid painful compression of 
living tissues. Such ought to be and such are indeed the physical 
properties of the horn. 
If the horn is superficially more or less dry, one must not 
conclude that a priori it has lost its watery element. It may be 
very dry on the surface and possess all its suppleness in its deep 
parts. Let us add that if this circumstance is not always the 
same, it is due not to an hygrometric condition changed by ex¬ 
ternal causes, but we believe, on the contrary, to a keratogenesis 
more or less abundant. 
In admitting that “ the element which keeps up the supple¬ 
ness of the horn,” had a natural tendency to evaporate, a fact 
which is doubtful, would it be a reason to conclude that this cause 
is by itself alone sufficient to bring on hoof-bound ? No ; for if 
it was so, this disease would be more common in common horses. 
And we know, on the contrary, that if it is frequent in some 
classes of horses, it is principally amongst private horses or of 
luxury, or in those whose hoofs are almost daily covered with 
greasy ointments to prevent their dessication. 
What we say for hoof-bound proper, we could repeat for the 
symptomatic quarter-crack. In the majority of writings upon 
this subject, it is said that the dry condition of the horn is one of 
the principal causes. If such were the case, rather than to appear 
as in a select spot, in parts closed to the coronary band, it would 
first show itself near the plantar regions, where the horn is de¬ 
prived of its natural varnish by external agents, by the rasp of 
the slioer, and where consequently it is more exposed to lose its 
watery element. 
To prove the influence of the dryness of the horn in the pro¬ 
duction of hoof-bound, many arguments were advanced. 1st. 
The curative influence of a thick and damp bedding, or of one 
made of fine damp sand, or of damp clay, was brought forward. 
But this influence is easy to explain without the assistance of the 
influence of humidity. In those conditions the frog touches at rest, 
and the plantar cushion may, to a certain extent, recuperate its 
vitality. 
