REVIEW. 
35 
Taking no further notice of the first two of these functions 
of the horny box, we arrive at the grand question of the 
Mechanism of the Hoof as an Apparatus of Elasticity. 
“ Elasticity, or, in other words, the property of deadening 
or stifling the commotions occasioned by the percussion of the 
foot against the ground, is produced within the horny box, 
1st, by the inherent property of the substance composing it; 
2dly, by the vast relative extent of surface it presents for 
appui; 3dlv, by the mechanical arrangement of the different 
parts entering into its composition.” 
Although the first two of these assist, but in different ways, 
in warding off the effects of concussions, it is the last in par¬ 
ticular which physiologists regard as (par excellence) the con¬ 
trivance for carrying this important operation into due effect. 
This interesting inquiry M. Bouley divides into two parts. 
First, he enters into a history of the different “ systems” that 
have been offered in explanation of the elasticity of the hoof; 
and, secondly, he gives his own views of the much agitated 
question. 
“ History of Elasticity of the Hoof. 
“ Lafosse’s (senior) notion was, that the hoof possessed an 
elasticity of its own, owing entirely to the property of flexi¬ 
bility inherent in the horn of which it was composed, which 
rendered it capable of yielding to pression at whatever part it 
might be applied, of adapting itself to irregularities of ground, 
and of serving as a protection to the parts it incloses.”— 
“ Evidently, Lafosse imagined that the flexibility of the hoof 
amounted to no more than that of caoutchouc, yielding to 
pression, and returning on the cessation of that pression to its 
original form. 
“ Now, this falls far short of the views Bracy Clark has so 
well developed in his (remarkable) treatise on the organization 
of the foot of the horse. 
li According to the learned English veterinarian, elasticity 
is a property possessed by the entire horny box, the result 
not only of qualities inherent in its substance, but , especially 
and principally, of the mechanical disposition of its different 
constituent parts. In the conception of Bracy Clark, the hoof 
is a veritable mechanical apparatus, admirably contrived for 
re-action, after the manner of an elastic spring, under the force 
of pression, in which manner is completed the entire machinery 
(ensemble des rouages) of the locomotive system.” 
We subjoin, in his own words, 
