62 
EXPERIMENTS ON THE FOOT OF THE HORSE. 
Here was a phenomenon, and (excuse the alliteration) a philo- 
sopher, who, conceiving a new idea, sought to establish its truth 
by direct experiment. 
The reasoning runs thus : — Since those marks could not have 
been produced either by lateral expansion or descent of the sole 
(to both of which there, doubtlessly, already existed a prejudice), 
there must be a downward and backward action taking place. 
To establish this idea, and, at the same time, disprove former 
theories of “expansion” and “descent,” experiments must be 
instituted. 
The action was to be tested by removing from beneath the heels 
of the foot every resisting body which could oppose their supposed 
natural descent (the best means which could be devised for this 
purpose appears to have been the “shoe much sprung at the 
heels”), whilst, at the same time, lateral expansion and descent 
of the sole were simultaneously encountered by means of well 
tempered wax. 
Passing over details, and arriving at the peroration, we find 
Mr. Gloag thus expressing his deductions : — 
“There is no appreciable lateral expansion of the quarters of 
the foot at the lower circumference under any circumstances of 
shoeing, the only expansion which takes place being by gradual 
growth.” * * * 
“ In ordinary shoeing, the base of the frog is a fixture * * *, its 
descent being entirely governed by the descent of the heels.” 
“That there is no appreciable descent of the horny sole in 
moderately concave feet under ordinary circumstances of shoeing,” 
nor is there “ sufficient descent of the sensible sole, under ordinary 
circumstances, to impede the circulation of blood in the foot ; and 
that those beautiful provisions in the foot for the carrying on of 
the circulation seem rather designed to remove the possibility of 
obstruction to the course of the blood, than as the general means 
by which that circulation is forced onwards.” 
Furthermore, from experiment, he finds, “ that when a shoe 
gently set off at the heels be nailed to the foot, the heels will 
descend until they touch the shoe.” 
He then observes, “ That in a horse in a state of nature, or 
shod with the heels sprung, a certain action of the foot goes on in 
addition (to the backward and downward action previously de- 
scribed), namely, a slight declination of the whole hoof in the 
direction of its fibres ; thus allowing the heels and the base of the 
frog to descend, which I consider to be the natural action of the 
foot, and that by shoeing we prevent this natural backward and 
downward action.” 
