534 THE THIRD HUXLEY LECTURE 



simply, as I believe, by aid of the principles which we have been discussing. 

 Mechanical violence is a noxious agency producing effects proportionate to its 

 degree. A very blunt implement passing through the tissues kills the surface 

 of the parts which it divides ; and in former days we had to poultice a ' contused 

 wound ' till the sloughs separated. A sharp knife does not destroy any part 

 of the tissues, but it throws them in a microscopically thin layer into a state of 

 intense inflammatory congestion, attended with effusion of coagulable liquor 

 sanguinis. But this noxious agency is only momentary in its operation. It has 

 no time to cause active congestion through the nervous system, but at once 

 leaves the injured tissues free to recover by virtue of their own inherent powers. 

 If the instrument be very sharp the layer of lymph will be very thin, unless 

 some other disturbing cause come into play. But it is always sufficient in 

 amount to serve the beautiful purpose of adhesion. 



It is comparatively rarely that direct inflammation is met with thus pure 

 and simple in practice. The two forms, the direct and indirect, are commonly 

 more or less associated. Thus putrid discharge in a wound is an acrid irritant, 

 as I once experienced personally in the keen smarting of an abrasion on the back 

 of my hand, smeared accidentally with the pus of a stump that I was dressing. 

 Hence during the period that elapses before the divided tissues are clothed with 

 that wonderful protecting layer which we term granulations, such discharge 

 causes direct inflammation in the structures on which it acts immediately, 

 while it also induces in them and in neighbouring parts inflammation through 

 the nervous system. 



When Marion Sims had published his remarkable success with the silver 

 suture in gynaecology, I resolved to give it a trial in general surgery. At that 

 time, as assistant surgeon in the Royal Infirmary of Edinburgh, I had charge 

 of the Lock Hospital ; and one of the patients having an atheromatous tumour 

 of the scalp, I removed it and brought the edges of the skin together with a silver 

 stitch. No vessel required ligature, and the wound healed without suppuration. 

 As the suture created no disturbance, I left it in situ for about ten da3^s, when 

 I took the patient over to Mr. Syme and showed him the skin about the wire 

 perfectly pale and natural in appearance without a trace of discharge, whereas 

 a silk stitch would within four days have infallibly caused suppuration, with 

 surrounding redness. Mr. Syme at once recognised the importance of the 

 facts, and from that day forward the silver suture was used for all wounds in 

 the clinical wards, until, some years later, antiseptic measures caused it to give 

 place to the more convenient and no longer hurtful silk. 



In thinking over this striking difference between the effects of the two 

 kinds of suture, it seemed to me clear that it depended on the silk imbibing 



