ANIMAL PATHOLOGY. 
The caustic was an efficacious preventive—the cautery was per¬ 
fectly useless*. 
What caustic, then, should be applied ? Certainly not that to 
which the surgeon usually has recourse—a liquid one. Certainly 
not one that speedily deliquesces; for they are both unmanage¬ 
able ; and, what is a more important consideration, they may 
hold in solution and not decompose the poison, and thus inocu¬ 
late the whole of the wound. 
The caustic which, during many a year, I have been in the 
habit of using, and which has in no instance deceived me, is the 
Lunar caustic. It is perfectly manageable, and, being sharpened 
to a point, it may be applied with certainty to every recess and 
sinuosity of the wound. 
The potash and the nitric acid will destroy the substances with 
which they come in contact, but the combination of the caustic and 
the animal fibre will be a soft or semi-fluid mass. In this the virus 
is suspended, and with this it lies, or may be precipitated upon, 
the living fibre beneath. Then there is danger of re-inoculation, 
and it would seem that this fatal process is often accomplished. 
The eschar formed by the lunar caustic is hard, dry, and insolu¬ 
ble. If the whole of the wound has been fairly exposed to its 
action, an insoluble compound of animal fibre and the metallic 
salt is produced, in which the virus is wrapped up, and from 
which it cannot be separated. In a short time the dead matter 
sloughs off, and the virus-is thrown off with it. 
Previous to applying the caustic it will sometimes be necessary 
to enlarge the wound, in order that every part may be fairly got 
at: and the eschar having sloughed off, it will always be prudent 
to apply the caustic a second time, but more slightly, in order to 
destroy any part that may not have received the full influence of 
the first operation, or that, by possibility, might have been inocu¬ 
lated during that operation. 
Does any chemical combination take place ? Is the virus neu¬ 
tralized by its union with the caustic? I cannot demonstrate this, 
but I have much reason to believe that some effect of the kind is 
produced. 
It seemed to be a dangerous and a fearful course of practice 
that for many a year I was pursuing. The number of rabid dogs 
that were brought to me, and of persons bitten by rabid dogs 
* “It is amusing to see the various disputations that have taken place 
with regard to the actual cautery. The kind of metal that should be 
employed was gravely debated, whether it should be gold or silver, or cop¬ 
per or iron : and when the cautery did not succeed with any of these, super¬ 
stition whispered that, haply, the keys of the church might triumph, and 
those of St. Peter, and St. Hubert, and St. Roch, and a host of canonized 
worthies, were tried in turn .”—Murray on Hydrophobia, p. 55. 
