DETAILS OF ANTISEPTIC SURGERY 223 



dispersed. It follows, therefore, that the presence of the fluid within the sac was 

 of itself sufficient to perpetuate for an indefinite period the state of chronic in- 

 flammation. And this fluid being the bland liquor sanguinis, perfectly destitute 

 of chemically irritating quahties, the only possible way in which it could have 

 produced its effect is by mechanical disturbance occasioned by its presence in 

 the sac. In other words, the agency by which the chronic bursitis was 

 maintained was that which, next to putrefaction, is the commonest of all causes 

 of inflammation in surgical practice — viz. tension. Yet, in cases of this kind, 

 the sac is by no means always extremely distended ; but, flaccid though it may 

 be, the fluid present in it keeps up by its mechanical influence the tendency to 

 abnormal effusion from the synovial surface and inflammatory hypertrophy 

 in the surrounding tissues. It seems to me important that this point should 

 be capable of being thus clearly demonstrated ; because the knowledge that 

 a flaccid collection of liquid acts as a cause of disturbance not only serves to 

 explain the obstinacy of chronic serous and synovial effusions, but throws light 

 upon other important matters, such as the prejudicial effect of even a slight 

 accumulation of serum within a wound, as in the aneurysm case above related, 

 or the influence of the presence of the contents of a slack chronic abscess in 

 maintaining suppuration from the pyogenic membrane. And, conversely, this 

 knowledge enables as to understand the benefit often obtained by simply 

 evacuating serous or purulent collections, either as a single remedial measure 

 or as a preliminary to counter-irritation. 



When the evacuation is effected in such cases by means of the aspirator, 

 the piercing cannula should be dipped into carbolic oil before introduction. And 

 if, as is often the case, the narrow tube becomes obstructed by lymph or curdy 

 material, there is no objection whatever to the use of an ordinary cannula and 

 trocar of any size that may be necessary, provided that the instruments be 

 smeared with the antiseptic oil and the operation be performed under the spray. 

 In abscesses, however, according to my experience, a cure rarely results from 

 evacuation of the contents by an opening which is allowed to close. The plasma 

 which exudes from the pyogenic membrane after withdrawal of the pus will, 

 if retained, nearly always occasion sufficient tension to reproduce suppuration. 

 But if it be allowed to flow freely away through a drainage-tube, under an 

 antiseptic dressing, the pyogenic membrane being freed from the disturbmg 

 cause which urged it to perpetual suppuration before the abscess was opened — 

 viz. inflammatory excitement occasioned by tension (greater or less according 

 to the degree of acuteness of the case), while the granulating sac is protected 

 from the new stimulus to which it would be subjected if the abscess were opened 

 without antiseptic measures — viz. the chemical irritation of putrefying material — 



