456 TREATMENT OF CANKER. 



white, and crumbles away or peels off under friction like so 

 much milk-curd ; and the sinuses along the sides of the frog 

 and bars, from which issued more discharge than from anywhere 

 else, appear dried up. This, which may be regarded as an 

 amended condition of parts, in contradistinction to that state of 

 the diseased foot in which the dressings come off soaked with 

 the discharges, must not, however, be suffered to delude us into 

 a hope that no repetition of caustic will be necessary. Caustics 

 or escharotics in some form will be required so long as any 

 fungus, or disposition to engender fungus, remains, and until the 

 clefts and crevices be not only dried up, but present at their 

 bottom red granulating surfaces, with clear white borders of 

 sound though soft horn. 



A Second and a Third Caustic Dressing may be called 

 for ; though, having reference of course to the nature and in- 

 tensity of the particular case, some modification may be re- 

 quired in the application of the dressing, as well as in the 

 dressing itself. There may be only certain parts which now 

 need the strongest corrective ; or, we may choose to employ 

 the butter of antimony in lieu of the nitric acid. Some places 

 indeed, not generating fungus, but simply issuing ichorous se- 

 cretion, will be best corrected by a milder caustic, such as 

 sulphate or acetate of copper. For it may be here observed, 

 in cankerous affections we make use of two distinct kinds of 

 caustics ; the one erodent, eating off the substance to which it 

 is applied, such as the nitric acid, the butter of antimony, &c. : 

 the other, simply escharotic, productive of slough ; such as are 

 the sulphate and acetate of copper, bichloride of mercury, arsenic, 

 sulphate of zinc, &c. Fungous excrescences will at all times 

 require erodent caustics; while morbid secreting surfaces, and 

 parts indisposed to throw up granulation, may be left to es- 

 charotics. The grand difference to be observed between the 

 treatment of ulceration of the foot and common sores in other 

 parts of the body, consists in the pressure found to be so salu- 

 tary and requisite for the former. The foot being a part which, 

 from its natural habits, may be called the organ of pressure, the 

 same influence appears indispensably necessary to it under 



