In every case in which the eschar does not separate favourably, I begin to suspect the formation of a scab underneath, in which case the whole must be removed by the application of a cold poultice for two or three days; this has not only the effect of removing the eschar but of allaying any inflammation or irritation; afterwards the caustic must be reapplied as before.
The gold-beater's skin is more useful as a protection to the unadherent than to the adherent eschar, as the former would be more liable to be torn off by accident than the latter. The gold-beater's skin must be removed in the manner already described, whenever the subjacent fluid is to be evacuated, and must be reapplied after touching the orifice with caustic.
The pain experienced on the application of the caustic is greater or less according to the sensibility and size of the wound. In small wounds it is trifling, and of short duration; it is more severe in recent wounds than in ulcers; it soon subsides in every case, and then the patient enjoys greater ease than would be experienced under any other mode of treatment. Little or no pain is caused on applying the caustic after evacuating the subjacent fluid of an unadherent eschar. Altogether the pain inflicted by the caustic is far less than is generally imagined, and forms scarcely an obstacle to its employment.
It may be proper, in this place, to notice such circumstances as render the employment of the caustic improper or inefficient. It is improper to employ the caustic when the ulcer is too large to admit of the formation of a complete eschar; or when it is so situated as to render it impossible that the eschar should remain undisturbed, as between the toes, unless, indeed, the patient be confined to his bed;--or in cases attended by much inflammation, or by much oedema.
I have found no kind of caustic so manageable as the lunar caustic; and this is best applied in the solid form. I have thought too, that the newly prepared lunar caustic is more apt to dissolve on being applied than that which has been longer made and more exposed to the air; the latter is therefore to be preferred.
III. ON THE TREATMENT BY ESCHAR AND POULTICE.
In many cases in which it is impossible to adopt either the mode of treatment by the adherent or the unadherent eschar, it is of great utility to apply the caustic first and then a cold poultice made without lard or oil: this plan is particularly useful in cases of punctured wounds attended by much pain and swelling, and in cases of recently opened abscesses. By this application the pain and swelling are much subdued and a free issue is secured for the secreted fluid; and in no case have I seen the original inflammation increased by it.