776 DISEASES OF THE WITHERS. 



obviate its action upon tlie tissues with which it comes in contact 

 and prevent its necrosing influence, and second to accelerate the 

 ehmination of the necrosed parts. 



The first indication is fulfilled in enlarging the fistulas to the 

 greatest extent possible. This is done with the straight bistoury 

 carried in the groove of the director or of the S probe, introduced 

 into the tract as far as possible. But when the fistula runs ob- 

 liquely downward and inward, and has become complicated with 

 diverticulums which run into the depths of the tissues, this en- 

 largement of the fistula is more difficult, inasmuch as it necessi- 

 tates too extensive a division of tissues for safety. This difficulty 

 is obviated by establishing counter-openings at points correspond- 

 ing with the bottom or cul-de-sac of the fistula. 



The situation of these counter-openings must be carefully cal- 

 culated in order to make the drainage perfect. The instruments 

 most suitable are the dog seton needle, a curved trocar, or prefer- 

 ably the S probe, and a straight bistoury. The openings must 

 be liberal to assure the best results, and they must be prevented 

 from contracting or too rapidly closing, and so checking the pur- 

 ulent flow either by the introduction of a tent of oakum or other 

 permeable foreign substance, or, and it is much the better method, 

 by the use of a drainage tube similar to the India rubber ii-riga- 

 tion tube. This implement, besides fulfilling all the other indica- 

 tions desired, possesses the additional advantage of facilitating 

 the injection of fluid detergents or curatives into the fistulous 

 tract. When the drainage has become well established irrigations 

 must be made two or three times daily as long as may be neces- 

 sary. The fluids best adapted as being both detergent and cura- 

 tive in their natui*e are pure tepid water, phenicated water (five 

 per cent, solution), or permanganate of potash solution (one to 

 two per cent.), or again simple alcoholic water. The irrigation 

 can be made with an ordinary syringe. Peuch and Toussaint, 

 however, say " that when the circumstances allow it cold water in 

 continued irrigation constitutes the best medication and that 

 which prevents most certainly all comjDlications. On that account 

 they cannot recommend it too strongly." 



While this form of treatment is usually successful in cases of 

 lesser severity, there are many instances in which they become 

 powerless, and other means become necessary for the removal of 

 the necrosed part. In times gone by caustics, in both the solid 



