236 ON DISEASES OF THE DENTAL APPARATUS 
whose number of applications must be regulated by the quantity 
of suppuration of the sinus, which diminishes daily, and changes 
its aspect according as the pyogenic granulations disappear from 
the surface of the membrane. By degrees this membrane loses 
its inflammatory turgescence, and gradually finishes by throwing 
off only a muco-purulent secretion in small quantity. 
However energetic may be the work of cicatrization under 
these circumstances, it is never sufficiently complete to entirely 
repair the structures cut away in performing the operation : for, 
in the first place, although the parietes of the sinus, in ordinary 
cases of trephining, do throw out callus at the border of the open- 
ing made b}' the trepan, and in time, by the process of extension 
and ossification, close the aperture, yet in the case of the operation 
which we have above described, the loss of structure is too great 
to be ever entirely replaced. This inconvenience, however, is more 
than counterbalanced by the advantages derived from its appli- 
cation. By its employ we have, in fact, obtained the cessation of 
the discharge from the nose which rendered the animal suspected 
of glanders, which disease, indeed, we feel confident is often ex- 
cited in consequence of the persistence of the former malady ; and 
the modus operandi of the production of glanders in such a case 
has a very plausible explanation on the grounds of the absorption 
of unheathy pus acting on a bad constitution by the effects of the 
dental disease — effects which have placed the animal entirely be- 
yond the capability of service. 
With respect to the opening at the facial region, that may be 
easily hidden by a leather or metallic plate attached to the check 
of the bridle. Again, its inconvenience is greatly counterbalanced 
by advantageous opportunities of injecting the sinuses, and pre- 
venting any unhealthy secretion from them. 
If, now, we consider this operation relative to one of its prin- 
cipal advantages, namely, the cessation of the jetage caused by a 
pathological modification of the membrane of the sinuses and the 
accumulation of pus in their cavity, we are struck with the efficacy 
of its results, especially if we compare them with the results of 
trephining in the case of collections in the sinus under the in- 
fluence of a specific cause , namely glanders. 
Wherefore this difference so complete 1 — Is it justly attributable 
to the cause being specific in the second case, and to the simplicity 
of its local action in the first? But we every day see the farcy, 
which may be considered as a glandered affection of the skin, re- 
cover under the influence of the different modifying agents that we 
employ ; but the glandered eruptions of the nasal cavities recover 
sometimes either by a spontaneous effort of nature, or by the action 
of our medicinal agents, when there do not exist in the sinuses 
