THE ART OF SHOEING SIMPLIFIED. 
129 
coffin bone, in conjunction with a corresponding- number of horny 
laminae lining the crust, are known to be the sustainers of the super¬ 
incumbent weight in the unshod natural foot, by forming a sort of 
dove-tailed union of immense strength. These numerous elastic 
springs elongate under the impression of the weight in direct 
ratio to the momentum or force, and w hich is accompanied with 
a corresponding relaxation or yielding of the horny box through¬ 
out at the same instant; by which concussion to the foot is ob¬ 
viated, and the animal himself preserved from jar. On the other 
hand, we w ill suppose a three-year old colt, and, to avoid ex¬ 
tremes, say about the hackney size, three parts bred, with fair 
formed limbs, and sound hoofs of becoming size, neither too Hat 
and low, nor too upright and strong, to be well shod in the ordinary 
way for the first time, and w ith a seated shoe of 'equal thick¬ 
ness toe and heels, secured by eight nails, four on each side or 
quarter, as usual. From the very first moment that this animal 
steps out of the forge upon the new surface interposed between 
his foot and the ground, his tread becomes uneven, although 
the foreign body which is appended to the foot is as level as a 
die. Now the elastic laminae also sustain the weight in this fresh 
shod colt, the impression of which has a tendency to elongate 
the laminae to the same extent; but no, the fetter is upon the foot, 
atid the best formed shoe that the art of man can devise, if nailed 
to both sides and quarters of the hoof, according to the mode in 
general use, will, from that very hour, limit , though it cannot 
altogether deprive the laminae of their elongation. The laminae 
covering the anterior and lateral portion of the coffin bone, w ill, 
on the instant, suffer some deprivation of function, just barely 
sufficient to disturb the harmony of the mechanism. The horny 
sole, however, notwithstanding the rigidity of the shoe and nails, 
will continue to descend in part , and will yield to the im¬ 
pression of weight and force united. It is this partial or 
imperfect descent of the coffin bone and horny sole to which I 
am anxious to draw your attention. It is quite obvious that 
the unshod horse in a state of nature exercises equally 
the whole five hundred laminae or elastic springs, by their 
elongation the coffin bone descends within the crust, under 
the impression of weight, from which pressure on the horny 
sole its arch sinks, and spreads uniformly in all directions, 
toe as much as heel , whilst every portion of the coffin bone 
which is in contact with the wall or crust also assists in 
dilating the base of the foot, and expanding the toe as well as 
the heels. I lie w eight being removed, all these parts, by 
virtue of their own elasticity, instantly return to their former 
position, in readiness for renewed action ; and undoubtedly the 
VOL. IV. T 
