expansion of the horse’s foot. 319 
Result .—The heel which was at liberty descended, but not to 
the same extent as when both were at liberty. 
\lth Experiment. 
Similar experiments were made on the dead fore foot of a cart¬ 
horse in the vice, by giving pressure by means of a piece of wood 
accurately fitted to the coronet bone, this piece of wood and the 
shoe being the opposing surfaces. 
Result .—On the pressure being applied and continued, the whole 
foot yielded backwards and downwards, until the heels of the foot 
touched the heels of the shoe, beyond which it could not descend. 
On the pressure being relieved the parts resumed their natural 
position. 
Observation .—This appears to me the natural action of the foot, 
that is, to yield slightly downwards and backwards in the direction 
of the fibres. On looking at a shoe taken off a horse’s foot, we 
often see, besides a brightening at the heels, a regular indentation 
in the iron, as if it were caused by constant pressure : it may be 
that, instead of there being any lateral expansion when the foot 
comes to the ground, there is a slight contraction, from the bulging 
out of the superior parts of the hoof; and in support of this we 
may further notice, that this brightening of the shoe at the heels 
never proceeds outwards, but rather inwards. Practitioners are all 
fully aware what great relief of lameness is obtained, in many cases, 
by merely springing the heels; hence also the extensive use of the 
bar-shoe (not pressing upon the heels), which, by the elasticity of 
the frog, allows a certain degree of freedom to the heels. 
Many farriers succeed in giving ease to a lame horse by shoeing, 
whilst others fail in doing so; and most frequently this is done by 
springing the heels and making the shoe wide and easy: these 
cases are of every day occurrence. Again, how many horses, on 
being fresh shod, go tenderly and painfully, and after a few days 
all is well again. May not this arise, partly, from the shoe being 
laid firmly to the heels, and after a few days a certain degree of 
wear taking place of the inferior border of the crust at the heels 
and quarter of the foot, the natural action and freedom of the animal 
being so restored ] How many lame horses obtain ease by placing 
fresh leather under the seating of the shoe, or sometimes only under 
the heels and quarters. Cloth and felt are used extensively by 
horse proprietors in this way, and they can attest their value; and 
may not the ease obtained by the use of these articles be accounted 
for on these principles] I believe practitioners will agree with 
me, that a shoe having a strong bearing at the heels is prejudical 
lor general use, however they may differ from me in the rationale. 
