The Sun.
London, England, 1866-04-11 00:00:00

From this superficial anatomical sketch, it w

easily be seen how great a nervous relation exists
between the organs of digestion and respiration. It
will be readily understood how impressions made
upon the organs of digestion will affect those of re-
spiration, and produce inflammation of them, but
by what means these bad impressions are obtained
is beyond our present power to discover. We must
therefore rest satisfied with the knowledge of the
effect of which some omnipotent force as yet un-
known is the cause.
"The manner in which the will is conveyed to the brain,
or how sensations are excited in different parts of the body,
remain involved in mystery. The author of nature is per-
fect in all his works, and although we do not understand
all the workings of his hands, we are compelled to acknow-
ledge their wisdom, propriety, and beauty."—Beaumont.
Much remains for physiologists to discover con-
cerning sympathetic action. That it is a pheno-
menon taking place every moment we all know,
"for whether one member suffer all members suffer
with it, or one member be honoured all members
rejoice with it," but by what means the result of
sympathy is made manifest, remains for future
physiology to determine.
In my letter of last week I attempted to prove
the theory of inflammation, as previously explained,
to be correct, changing theory into fact by adducing
examples of disease of not uncommon occurrence
among horse and cattle, as congestion of the lungs ;
it will now be my endeavour to apply in practice
that which theory has suggested, and in so doing, to
point out the results of inflammation, or, in other
words, to enumerate a number of diseases occurr-
ing consequent upon the withdrawal of nervous
force, either locally or generally ; and in the first
place shall detail those maladies involving the boxy
tissue in inflammatory action.
Splints.—Very few horses live who are not
affected, more or less, with the disease denominated
" Splint." A splint consists of a bony tumour,
generally situated on the inside of the foreleg, which
is composed below the knee of the following bones :
—The cannon (metacarpus) and small metacarpal
bones, situated behind the cannon, the one inter-
nally and the other externally.
In the colt the metacarpal bones and cannon are
united together by a fibro ligamentous substance,
but as age advances, ossification of this structure
commences, and, finally, the cannon and small meta-
carpal bones are cemented together by, bony union,
or, in other words, those three bones farm one com-
mon shaft. Usually at five years old, while the pro
cess of ossification is progressing, the animal is daily
performing severe physical exertion, and the result
is that, owing to the causes to be afterwards con-
sidered, the horse " throws out," as it is called, a
splint.
Let us consider how it is that the fibro cartilagin-
ous substance:existing between the cannon and meta-
carpal bones becomes converted into bone. Perci-
vall writes :

"The immediate or proximate cause we believe to be
increased action, amounting in some instances to inflam-
mation set up in the vessels of the fibro cartilage, whereby
hypertrophy or exostosis (growth of bone from bone) is
produced."
I cannot agree fully with the opinion of Mr. Per-
civall, which considers that the conversion of the
fibro cartilage into bone is due to a deviation in the
part from health. When the bony depositions pro-
ceed beyond their limits, that is, grow out beyond
the space occupied by the primary substance—viz.,
the fibro cartilage, and by their aggregation form a
tumour, then, doubtless, the disease splint is set up,
but the conversion of cartilage into bone is no ab-
normal condition of the part, but simply a natural
consequence occurring prematurely—that is, before
the full development of the animal tissues.
My reasons for arriving at this conclusion are that
in foetal life the skeleton is composed of cartilage,
which becomes gradually converted into bone. Even
at birth many of these bones are not united toge-
ther, but during months in the life of the lower ani-
mals, and years in that of man, they are undergoing
a gradual change from cartilage into bone. In
order to make myself clear on this, let me remind
the readers of the Gazette that bony tissue is com-
posed of two materials—viz., of animal and calcare-
ous matters, the former giving elasticity, and the
latter hardness ; the amount of animal matter in
young animals is large, whereas in old ones it gives
way to the calcareous or earthly material, and