AS A SURGICAL DRESSING 303 



from that dressing chloride of mercury, still in solution, though associated with 

 albumen, and still retaining antiseptic properties. 



I may conclude this matter of the relations of the blood-serum to corrosive 

 sublimate by showing some illustrative specimens. I found that, if serum is 

 mixed in small proportions with corrosive sublimate, in a mortar, the result 

 is the production of a thick, opaque, slimy material ; but if you add a little 

 more, and still a little more, you get this material redissolved in the serum, 

 until, if you use as much as 150 parts of serum to one of sublimate, you get 

 a clear solution. This test-tube contains serum from the blood of a horse, 

 mixed with one two-hundredth part of corrosive sublimate. You will see that 

 there is no precipitate here at all. This other test-tube contains the same 

 amount of corrosive sublimate (i to 200) ; but the liquid mixed with it, instead 

 of being serum simply, is serum with an equal part of distilled water ; and 

 here we have what the chemists describe as a precipitation of the albumen, 

 the upper part of the liquid being clear. Now, this upper part of the liquid 

 contains exceedingly little corrosive sublimate ; it has almost all gone down 

 with the albumen ; but if we take some of this precipitate itself and mix it with 

 more serum, it will be redissolved by that serum. This afternoon, I mixed some 

 of this precipitate with some serum already containing one four-hundredth 

 part of sublimate, and the result has been the clear solution that you see here. 

 This albuminate, if we are to call it so, is therefore highly soluble in blood-serum, 

 and that is one important point to which I wish to direct attention. 



While the sublimate is thus, so to speak, intact when associated with 

 albumen, it is rendered very much milder in its action. I took some of the 

 serum which had come through the 10 per cent, wool, containing one part of 

 corrosive sublimate to 160 parts liquid, soaked a piece of lint with it, and applied 

 it to my arm, put over this a piece of thin macintosh cloth, to prevent evaporation, 

 and secured this with rubber adhesive plaster. I retained this dressing in position 

 for twenty-four hours, and on its removal found an absolute absence of any 

 irritation, although my own skin is pretty sensitive. We have seen how, in 

 twenty-four hours, one part of sublimate to 500 of water already }:)roduced 

 pustules ; yet here one part to 160 of serum produced no irritation whatever. 

 The association, then, of the albumen with the corrosive sublimate greatly 

 mitigates its action, and makes it much less irritating. Thus we are able to 

 understand how the discharges coming from a wound soaking a sublimate 

 dressing may not cause irritation, although the dressing may contain a large 

 proportion of corrosive sublimate. Such being the case, I hoped that we niiglit 

 be able to use corrosive sublimate in pretty strong proportions in a gauze lor 

 the dressing of wounds ; and therefore, not very long ago, in a case of psoas 



