602 OPERATIONS ON THE FOOT. 



surface, of modifying agents which influence the nutritive and 

 secreting functions of their tissues without interfering with their 

 structure. To reach this point, the most varied pharmaceutical 

 agents have been recommended, the most successful being those 

 which at the same time had parasiticide properties. We, however, 

 find it difficult to give the preference to any of them ; and we have 

 now more faith in the inodus faciendi, to the skill of the operator, 

 to the continued use of dressings properly applied, than to such 

 or such agent; all of those which have been recommended if 

 methodically applied, can cure canker, and it will be wise to em- 

 ploy them alternatively ; when one fails at first it is prudent to 

 try another ; canker is a disease so often rebellious to treatment, 

 especially when confined to the lacunae of the frog, that too many 

 remedies cannot be used. 



The first indication is to remove the excess of the horn of 

 the waU, the length of which, we have said, is often very great; 

 then prepare a convenient shoe for the dressings. This shoe nec- 

 essarily varies, as canker is exclusively localized to the plantar 

 surface of the foot or extends to the podophyllous laminae. Gen- 

 erally an ordinary shoe is used, more or less covered (wide) and 

 so hollowed as to allow the free application of plates by which 

 the dressing is kept in place. When the condition of the disease 

 requires the removal of large pieces of horn, a truncated slipper 

 is used, proportioned in cutting to the extent of the parts of the 

 wall upon which it is to be appUed. There are circumstances even 

 when shoes cannot be used, so much does the disease extend 

 under the wall. It is then necessary to use a shoe without nails, or 

 boots, secured to the coronet by means of straps. In aU cases the 

 rule is to take care that the dressings remain fixed in the most 

 exact manner, and that through them a methodic, steady, but not 

 excessive pressure is constantly applied over the diseased parts. 



The first step of the operation passed, the next consists in 

 the removal with proper instruments of all the loose portions of 

 the horn, either at the plantar surface, at the quarter, or at the 

 heels. One must avoid, in this operation, the excision of soft 

 parts ; but the important indication is to follow the disease where- 

 ever it exists, and to leave no part of the horn which may have 

 been detached by morbid exudations. Better cut the healthy 

 structures, and have them bleed, than to neglect to completely 

 expose a diseased part. This done, the horn is to be thinned as 



