542 
ON SPLINTS. 
weight is directed to that part of the shoe. The degree of the 
evil will be in proportion to the deviation from the proper posi¬ 
tion of the limb. 
I need not enforce this fact, owing to every one acquainted 
with shoeing of horses knowing that the outside heel and quar¬ 
ter require to be kept stronger than the inner; and, after all, 
when the shoe is taken off, the outside is found nearly worn 
through, while the inner has but little suffered. 
Now if the toes are turned inwards, the effect will be just the 
contrary, as far as the parts will allow: the inner quarter and 
heel being weaker than the outer, they cannot be used with the 
same freedom as the outer; and what is more favourable to the 
legs of these animals is, that they are generally not possessed of 
much action. The causes of splint operate principally by acting 
on the carpus, throwing it outwards or inwards. As the latter 
is the most frequent, 1 shall first describe it. It may be conceived 
that, when this effect is produced, the oblique surface of the os 
unciforme, resting upon the small metacarpal, will be increased, 
while that on the large will be diminished; and that articular 
surface upon 'which the os magnum moves is likewise presenting a 
greater angle ; and these circumstances will cause a greater part 
of the diffused force or weight to be concentrated on the inner 
small metacarpal bone. 
When this irregular action takes place, the question merely is, 
whether the ligamentous connexion between the metacarpal bones 
is elastic enough, through its whole extent, to contend with that 
undue pressure ? In many instances, I say, the ligamentous sub¬ 
stance must be injured ; and the usual seat of injury is three 
inches below the knee. It is obvious that the inner metacarpal 
bone is united to the large throughout a space of six inches ; for 
the three lower inches the bones are closely in contact, w hile 
throughout the superior three the ligamentous substance gra¬ 
dually increases in width, till it arrives at a point where it ave¬ 
rages two-eighths of an inch. 
From the undue lateral pressure which may displace the upper 
part of the inner small metacarpal bone, I shall compute it to be 
one-eighth of an inch : the termination being at six inches in 
the centre, the common seat of splint, it will act wath immense 
force, at a part not containing one-tenth of the connecting liga¬ 
ment. 
This being the case, injury of the ligament at this part is ine¬ 
vitable. It may be argued, that at the superior part it cannot 
yield to the extent that I have stated : I would only remind such 
objectors, that the ligamentous fibres cross each other like an X, 
so that, instead of being two-eighths of an inch, they are, in 
