278 LORD LISTER 



maintains the suppuration is derived from the presence of 

 pus pent up within the cavity. When a free opening is 

 made in the ordinary way, this stimulus is got rid of, but 

 the atmosphere gaining access to the contents, the potent 

 stimulus of decomposition comes into operation, and pus 

 is generated in greater abundance than before. But when 

 the evacuation is effected on the antiseptic principle, the 

 pyogenic membrane, freed from the influence of the former 

 stimulus without the substitution of a new one, ceases to 

 suppurate (like the granulations of a sore under metallic 

 dressing), furnishing merely a trifling amount of clear 

 serum, and, whether the opening be dependent or not, rap- 

 idly contracts and coalesces. At the same time any con- 

 stitutional symptoms previously occasioned by the accumu- 

 lation of the matter are got rid of without the slightest risk 

 of the irritative fever or hectic hitherto so justly dreaded 

 in dealing with large abscesses. 



In order that the treatment may be satisfactory, the 

 abscess must be seen before it is opened. Then, except in 

 very rare and peculiar cases,* there are no septic organisms 

 in the contents, so that it is needless to introduce carbolic 

 acid into the interior. Indeed, such a procedure would be 

 objectionable, as it would stimulate the pyogenic membrane 

 to unnecessary suppuration. All that is requisite is to guard 

 against the introduction of living atmospheric germs from 

 without, at the same time that free opportunity is afforded 

 for the escape of the discharge from within. 



I have so lately given elsewhere a detailed account of the 

 method by which this is effected (Lancet, July 27th, 1867), 

 that I shall not enter into it at present further than to say 

 that the means employed are the same as those described 

 above for the superficial dressing of compound fractures; 

 viz., a piece of rag dipped into the solution of carbolic acid 

 in oil to serve as an antiseptic curtain, under cover of 

 which the abscess is evacuated by free incision, and the 

 antiseptic paste to guard against decomposition occurring 





8 As an instance of one of these exceptional cases, I may mention that 

 of an abcess in the vicinity of the colon, and afterwards proved by post- 

 mortem examination to have once communicated with it. Here the pus 

 was extremely offensive when evacuated, and exhibited vibrios under the 

 microscope. 





