DISEASES OF THE LATERAL CARTILAGES 347 



A better method, however, when the dressing lends itself 

 to the purpose, is to use it in the form of a powder, wrapped 

 in the form of small cubes in extremely thin paper, such, 

 for instance, as is used for rolling cigarettes. It is then 

 conveniently inserted into each fistula. Introduced in this 

 more finely divided form the drug is. perhaps, a little more 

 active in bringing about the desired result. 



This method of ' plugging,' although practised by many, 

 we cannot recommend in preference to the use of the hot 

 iron or of liquid injections. Our reasons are these: the 

 action of the drug is a protracted one. Almost immediately 

 after its introduction into the fistula there is formed about it 

 an almost impermeable layer of a metallic albuminate, which 

 effectively prevents further rapid action of the caustic. In 

 addition to thus preventing further action of the dressing, 

 this combination of the tissue albumin with the metal of 

 the salt, together with much necrotic tissue that it has 

 caused, is extremely hard to remove from the healthy tissues. 

 This we explain by pointing out that the action of the 

 caustic, prolonged as it is, sets up a tissue reaction which 

 partakes largely of the type of a chronic rather than an 

 acute inflammation. With a chronic inflammation there is 

 sooner a tendency to the production of fibrous tissue (and 

 thus the firmer attachment of the necrosed portions) rather 

 than an active phagocytosis and the casting-off of a slough. 

 Again, careful though we may be with the probe, it is 

 extremely difficult to be certain that we have discovered the 

 whole extent of any fistula An equal difficulty, therefore, 

 exists in being certain that we have placed the caustic in the 

 position in which it is most wanted.— namely, at the further- 

 most end of the fistula where the necrotic tissue is to be found. 



\\ nen a caustic is used at all, it is far better to employ it 

 in the liquid form, when either of the drugs we have just 

 mentioned may again be used. In the first place, the liquid 

 is far more likely to be brought into contact with the diseased 

 structures than is the solid salt. Also, its action may be 

 regulated by altering the strength of the solution, and the 

 liability to form impermeable albuminates thus diminished 



