THE BRITISH MEDICAL ASSOCIATION 185 



and was simply the result of the chemical action of the nascent sulphur upon 

 the discharges. And if, under such circumstances, we resumed the oiled silk 

 protective, we again had perfect absence of unpleasant smell. 



The necessity for avoiding any sulphur in the material was a great cause 

 of embarrassment ; for, as a general rule, the admixture of any foreign ingredient 

 with caoutchouc causes a most inconvenient softness and adhesiveness of the 

 product — evils which vulcanizing completely corrects. Magnesia forms an 

 exception to this rule, producing with the pure rubber a very satisfactory 

 substance as regards its physical properties. But then we found that, in the 

 case of a sensitive skin, this magnesia caoutchouc produced intolerable itching 

 and redness, for a reason which I do not quite understand. At length it occurred 

 to me that perhaps shellac, which seems quite unirritating, might be mixed 

 with the caoutchouc ; and that this might answer the purpose. Tor though 

 shellac, when once mixed with carbolic acid, holds it very tenaciously, as is 

 seen in the lac-plaster with which some of you are familiar, yet the acid does 

 not readily penetrate into unmixed lac. When I suggested this to the managers 

 of the india-rubber works, ^ they told me that they had previously ascertained 

 that shellac could be perfectly blended with caoutchouc ; the product being 

 the beautiful article you now see, sufficiently tough, yet pliant, transparent, 

 and with no unpleasant odour, and, as I ascertained by experiment, practically 

 impermeable to carbolic acid. Here, then, I thought I had attained the object 

 at which I had been aiming for years ; and already we were getting results 

 of a kind we had never got before : we had reached more nearly than ever 

 before the conditions which we know must occur subcutaneouslv. I had never 

 witnessed the healing of ulcers proceed so rapidly as I have seen it under this 

 protective, covered with overlapping gauze ; but, to my extreme chagrin, 

 I have learnt within the last few days that, in two patients with very sensitive 

 skins, even this material produces a trifling irritation. Still I cannot but believe 

 that we are on the verge of getting what we want in a protective — viz. a tissue 

 perfectly bland and unstimulating in its own substance, and also quite imper- 

 meable to the antiseptic. 



So much, then, gentlemen, as to our means ; and now. if you will allow 

 me a little time longer, I will tell you what I expect will be the most interesting 

 to you all — the history of some cases illustrative of the effects of this treatment. 



The simplest of all cases for antiseptic management is that of abscess ; 

 and the most beautiful, as it seems to me, in the results. It is the simplest, 

 because here we do not apply the antiseptic to the part concerned at all : we 



' I caniKJl but jniblicly express my thanks to the managers of the North Bntisli India-rubber Works, 

 for the great kindness and hberahty with wliich they have carried out these experiments for me. 



LISTER II O 



