their incipient
existence.

_Cause._--It is certain that inflammation of the periosteum is
frequently referable to wounds and bruises caused by external agencies,
and it is also true that it may possibly result from the spreading
inflammation of surrounding diseased tissues, but in any case the result
is uniformly seen in the deposit of a bony growth, more or less diffuse,
sometimes of irregular outline, and at others projecting distinctly from
the surface from which it springs, as so commonly presented in the
ringbone and the spavin.

_Symptoms._--This condition of periostitis is often difficult to
determine. The signs of inflammation are so obscure, the swelling of the
parts so insignificant, any increase of heat so imperceptible, and the
soreness so slight, that even the most acute observer may fail to find
the point of its existence, and it is often long after the discovery of
the disease itself that its location is positively revealed by the
visible presence of the exostosis. Yet the first question had been
resolved, in discovering the fact of the lameness, while the second and
third remained unanswered, and the identification of the affected limb
and the point of origin of the trouble remained unknown until their
palpable revelation to the senses.

_Treatment._--When, by careful scrutiny, the ailment has been located, a
resort to treatment must be had at once, in order to prevent, if
possible, any further deposit of the calcareous structure and increase
of the exostotic growth. With this view the application of water, either
warm or cold, rendered astringent by the addition of alum or sugar of
lead, will be beneficial. The tendency to the formation of the bony
growth, and the increase of its development after its actual formation,
may often be checked by the application of a severe blister of Spanish
fly. The failure of these means and the establishment of the diseased
process in the form of chronic periostitis cause various changes in the
bone covered by the disordered membrane, and the result may be
softening, degeneration, or necrosis, but more usually it is followed by
the formation of the bony growths referred to, on the cannon bone, the
coronet, the hock, etc.

SPLINTS.

We first turn our attention to the splint, as certain bony enlargements
that are developed on the cannon bone, between the knee or the hock and
the fetlock joint, are called. (See Plate XXV.) They are found on the
inside of the leg