64 
EXPERIMENTS ON THE FOOT OF THE HORSE. 
If the whole foot moves to accomplish 
the approximation between the heels and 
the set-off shoe, such approximation can 
only be effected by the rocking of the crust 
and springing of the nails, an effect which 
the annexed cut will illustrate. 
If the latter be the gentleman’s meaning, 
the plan would be at once precluded, by the 
tendency to spring the nails and cast the 
shoe. But I am much inclined to imagine that the former is the 
true interpretation, more especially upon perusing the following 
passages : — 
Experiment 15. — “To the near fore-foot a shoe was ap- 
plied, greatly sprung at both heels.” * * * “ The horse was now 
made to walk about, when I could perceive that the heels of the 
foot descended nearly to the heels of the shoe” (of course the nails 
did not spring, or Mr. Gloag would have mentioned it). “ On the 
foot being lifted, the heels resumed their natural position.” Again, 
in the observations upon Experiment 23, — The sensible sole 
is much thicker and less vascular at the heels of the coffin-bone, 
which is also tipped with cartilage, apparently to allow of this 
backward action of the foot.” 
Conceiving it, therefore, to be Mr. Gloag’s opinion, that the 
“ natural action” of the hoof consists of this bending downwards of 
the hinder part, we must, before alluding to the merits or demerits 
of his plan to provide for such action, first ascertain whether or not 
such action really takes place when the foot is perfectly uncon- 
fined, or in a state of nature. 
To resolve this question, I instituted the following experiment: — 
A horse was selected with a good, open, and moderately con- 
cave foot, elastic as healthy horn could have been wished. The 
near shoe was taken off, when the under surface of the crust 
appeared perfectly level from toe to heel. Previously, a slab of 
gutta percha (in size about a superficial foot square, and one inch 
in thickness) had been prepared by being softened in hot water. 
This being laid upon a smooth pavement, the horse’s foot was 
placed upon it, at the same time the other leg was held up, and 
the animal mounted. In this position the foot continued until the 
gutta percha had hardened by cooling, a process which was facili- 
tated by the application of cold water. 
The mould was then removed, and a plaster cast taken there- 
from. Now, had there been any downward bending of the heels, 
this cast would have exhibited the same ; but its under surface 
corresponded in every respect with the appearance of the foot 
