Encyclopaedia Britannica, or, a Dictionary of arts, sciences, and miscellaneous literature : enlarged and improved. Illustrated with nearly six hundred engravings > Volume 8, ELE-FOR

Part II.
Anatomy of blood borfes. Their paftern bones are lliort, and the
oftlie joints nearly ftraight ; bat thorough-bred horfes of
H^lfe' , light weight have long and very oblique paftern joints ;
’ and, as in proportion to the obliquity of the large
pattern, or fetlock joint, the canon conveys more of the
weight to the fefamoid bones, the ligaments that fup-
port the fefamoids are neceflarily put into motion, and
more on the ftretch, as the weight preffes down the
lower and back part of the canon on the fefamoid
bones. Short paftern joints are as much adapted to the
frame of heavy horfes as longer joints are to that of
lighter horfes. The ligaments that fupport the fefa-
moids above alfo contribute to afiift the flexor mufcles
and tendons in preferving when at reft, and in motion,
* Coleman the large paftern joint in its proper place*.”
on the Before we proceed in defcribing the ftrufture of the
, .. foot, it will be proper to (hew how the hoof is formed,
,2r and how it is connefted with the parts within.
Strudlure The hoof of the horfe forms a fort of organized {hoe,
of the hoof. vvhich is adapted to the foot with the greateft nicety 5
fo that every part of the cavity is completely filled,
without the foot’s being fubjefted to any unequal pref-
fure.
A correft knowledge of the natural form and ftruc-
ture of this part of the horfe’s foot, and of the deformi¬
ties produced in it by improper treatment, is of the ut-
moft importance; as on this muft depend the moft ad¬
vantageous method of {hoeing, and the only rational
means of correcting the unnatural deviations. It will
be obvious, that in order to form a juft idea of the ori¬
ginal thape of the hoof, we muft examine it before any
Ihoe has been applied to it ; for, unlefs this Ihoe has
been fo conttrufted and fitted to the foot, as to preferve
unaltered the original form of the hoof, this will be fo
changed, that we cannot recognife from it what was
the original ftiape. That the methods of {hoeing ufual-
ly employed are calculated rather to deform the hoof,
than to preferve its original figure, will appear pre¬
fen tly.
A vertical feCIion of the hoof {hows it to be nearly
conical; the broadeft part of the cone being next the
ground. This inferior furface, in a hoof that has not
been ftiod, efpecially in the fore foot, appears nearly
circular; or the diameter, from fide to fide, is nearly
equal to the diameter from toe to heel, (fee fig. 17).
The hoof is compofed of a horny fubftance that is
entirely without fenfation. It is divided into cruft,
Hz foie, frog, and barr.
Cruft. The cruft furrounds the foot on the fore part, and
on the fides, like a wall (A,- A, fig. 17). It grows
obliquely downwards from the coronet, and becomes
broader as it approaches the ground. It is thicker at
the toe than at the quarter ; and the outer quarter is
thicker than the inner. On the outfide it is fmootb and
rounded, but within hollow and laminated (B, B. fig.
15.) to unite with the coffin-bone. The cruft is the
only part into which nails can with fafety be driven in
123 {hoeing.
°rny lole. |)orny f()le (B B, fig. 17.) unites with the lower
part of the cruft, and is fituated below the coffin-bone ;
but between it and the coffin-bone, there is a vafcular
fubftance, to beprefently defcribed, called they^.v/rZA’Jo/e,
from the blood-veffels of which the horny foie is form¬
ed. On the outfide next the ground, the horny foie is
hollow, but rounded within next the coffin-bone. Tire
445
horny foie prote&s the fenfible foie from injury, and in Anatomy
the horfe’s motions it embraces the ground, afting as a °f the^
Hop. When the laminated fubftances of the hoof length- ^ e' ,
en, the horny foie defcends, and thus affifts in prevent¬
ing concuffion. I24
The bars, or binders, (CC, fig. 17.) are two horny Ears,
fubftances placed between the lole and the frog, and
forming at the heels a dole folid union with the cruft.
The fmall part of the bars called the toe, fometimes
reaches almoft as far as the toe of the frog. Within
the frog, the bars are laminated like the inner part of
the cruft, and are clofely united to the horny foie. The
bars on the outfide keep the horfe’s foot extended, and
within, they tend to prevent the feparation of the fen¬
fible foie from the horny foie. In the natural ftate of
the hoof, there is a eonfiderable cavity between the bars
and the frog on each fide. 125;
The frog (DD, fig. 17.) is that hard rounded pro-Frog,
tuberance, which weobferve in the middle of the lower
part of the hoof, pointed towards the toes, and expand¬
ed towards the heel like a wedge. In the middle of
this broad part, there is a fiflure (E,fig. 17). The ex¬
ternal frog is united within the hoof to a narrow fub¬
ftance of a fimilar ftiape, but of a more elaftie ftrudfture,
and poffeffing fenfation, and therefore called the fenfible
frog. This fubftance is connedled above with the
navicular bone, towards the back part ; and at the ex¬
tremity of the heels, it is united with cartilages on each
fide. The toe of the fenfible frog is united to the cof¬
fin-bone, but by far the greater part is behind this bone.
The back part of the frogs being united with elaftic
and moveable fubftances, admit of confiderable motion,
the frog riling when the hoof touches the ground, and
defeending when the foot is raifed. By the alcent of
the frog, the heels are prevented from contradling, and
the cartilages are expanded, fo as to afford the horfe a
confiderable fpring, whilft the form of this part fits it
for embracing the ground, and thus prevents the
horfe from flipping. The convex form of the frog clear¬
ly {hows that it was always intended to touch the ground,
and experience has fully proved, that, unlefs this con¬
tact takes place, the healthy ftate of this organ cannot
be preferved. It has been fuppofed that the frog is in¬
tended to defend the principal tendon or back finew ;
but Mr Coleman has ffiown that this-is a miftake. I2(J
The weight of the horfe is chiefly fupported by the Weight of
cruft, and not by the foie or frog ; for when thefe parts the horfe
have been removed, or by being difeafed, become foftnot^l’F"
and fungous,,and thus incapable of refiftance, it is f°und the foie and
that the cruft is ftili competent to bear the whole of the fr0g.
weight. If the foie and frog really fupported the
weight, it is evident that when thefe parts are removed
or difeafed, the foot would flip through the cruft. I2^
The union of the fenfible frog with the horny frog, Importance
and the connection thus formed between the fid os of ot the frog’s-
tbe fenfible frog, and the lower cartilages, effectually ftc®1.vlnS
prevents diflocation. When the horny frog touches the111
ground, both that and the fenfible frog afeend ; but
when by any means the horny frog is prevented from
prcffing on the ground, its proper funclions are fufpend-
td. The cartilages partake of the motion of the frog ;
and, in proportion as this receives preffure, they recede
from each other, and allow the fenfible frog to afeend
between them. But when the cartilages are rendered
immoveable by becoming bony, or by contraction of
the
F A R R I E R Y.