86 THE NEW POCKET FARRIER. 



fistula is in the cellular membrane, and is known to be 

 present when there is a small aperture or opening on 

 the surface of the body, from which a sanious or other 

 matter, either flows spontaneously, or may be pressed 

 out ; its depth and direction is discovered by introducing 

 a probe, or if its directions are various, as is sometimes 

 the case, warm water may be injected therein, which 

 will show the course it takes, if that is near the skin, by 

 elevating it ; and if it is too deeply seated to be thus ob- 

 served, the quantity of water thrown in will be a criterion 

 whereby to judge of the size of the cavity. The probe 

 will indeed discover whether or not the sinus runs upon a 

 bone, or if the bone be carious, which water will not do. 

 The various parts in which these ulcers are seated, and 

 the different circumstances which attend them, constitute 

 the chief difference betwixt one fistula and another. As 

 to prognostics, the thicker the cellular membrane is, or 

 the more strata, or layers of muscles one over another, 

 the more mischievous a fistula will prove. While it is 

 simple, and extends no farther than it can be wholly 

 come at by a knife, it may be easily cured, but when it 

 is situated in parts that render the use of the knife 

 hazardous, or when it is complicated with a caries of the 

 bone, the cure is often difficult if not impossible. When 

 fistulas which are not yet become callous, are compli- 

 cated with ulcers, the most expeditious relief is obtained 

 by laying them open to the bottom, if it can be done 

 without running any great risk, after which they are to 

 be cleansed and healed as simple wounds. Another 

 method of effecting a cure, is by pressing their bottoms 

 towards their orifices by the help of a proper compress, 

 which must be applied to its bottom after the ulcer is 

 cleansed, and proper applications have been put into the 

 fistula. Some practitioners reprobate all kind of injec- 

 tions, but when they lie so deep that their lower parts 



