EXPANSION OF THE HORSE’S FOOT. 
259 
even upon the heels, but only fastened by five nails. The surface 
of the frog and sole opposite this bar was then well oiled, and the 
space between the iron bar and the toe of the frog and the sole 
was completely plugged up with wax, pounded up into a soft con¬ 
sistence with tallow and turpentine, so that it would bear the 
slightest impress of the finger. The edges of the prepared wax 
were then pared clean and even with a knife, and the horse was 
now made to trot. 
Result .—There was a perceptible crack in the wax, about one 
inch behind the point of the toe of the frog, opposite to the navi¬ 
cular bone: the separation or crack appeared to be about the thick¬ 
ness of the back of the blade of a penknife. I repeated this experi¬ 
ment several times with the same result. 
3 d Experiment. 
Subject, the same. 
To the other fore foot a shoe was applied with a good seating, 
laid flat upon the heels, but only fastened by a few nails. This 
shoe had a flat piece of iron welded to its under surface from heel 
to heel: the intervening space between this iron bar and the frog, 
as in the last experiment, was filled up with prepared w r ax, the 
frog being first oiled. 
Result .—There was no perceptible crack or separation in the 
wax after the horse had been trotted: I was much surprised at 
this, and repeated the experiment several times, with the same 
result. 
Observation .—I always had an idea that the frog descended 
slightly, under any circumstances of ordinary shoeing : in fact, I 
considered it as a sort of truism up to this time; for I had long 
known by observation, that, when a horse’s heels were sprung, 
the posterior parts of the foot perceptibly descended. 
4 th Experiment. 
Subject, a heavy cart-horse, with a good foot, moderately con¬ 
cave. 
A common shoe, rather wide at the heels and quarters, was ap¬ 
plied, and laid evenly upon the heels, and only fastened by a few 
nails. The quarters of the foot were carefully oiled, and some pre¬ 
pared wax was then pressed upon that part of the shoe projecting 
beyond the foot at the quarters, and also against the side of the 
foot: the horse was now made to trot. 
Result .—After many trials, I could not detect that the slightest 
movement or impression had been produced in the wax. 
