310 AN ADDRESS ON A NEW ANTISEPTIC DRESSING 



sal ammoniac in that proportion I should get a much more workable arrange- 

 ment. On consulting chemical works I found that one-fifth of sal ammoniac 

 was exactly sufficient to produce with bichloride of mercury the salt long known 

 to chemists as sal alernbroth, a double salt of bichloride of mercury and chloride 

 of ammonium. I naturally wished to ascertain whether this addition of sal 

 ammoniac would impair or even destroy the antiseptic properties of the bichloride 

 of mercury. I therefore made experiments on the point, and I found that the 

 sal ammoniac associated in the form of a double salt with the bichloride of 

 mercury did not by any means impair its antiseptic properties ; on the contrary, 

 it improved them, so far at least as concerned that which we have to deal with 

 as surgeons, an albuminous fluid like the serum of the blood. Sal alembroth 

 and bichloride of mercury proved to be exactly equivalent weight for weight as 

 antiseptics in such a fluid. Each had to be used in normal serum of specific 

 gravity of about 1,025 ^^ the proportion of about i-i,oooth in order to prevent 

 altogether the development of micro-organisms. Those who are acquainted 

 with Koch's researches will consider this a very high proportion. Koch has 

 shown that in a solution destitute of albumen i-ioo,oooth part of bichloride of 

 mercury is sufficient to prevent the development of organisms ; but when we 

 have albumen present in the solution the case becomes altogether altered. 

 Albumen interferes with the antiseptic action of corrosive sublimate, and thus 

 in serum of the blood of specific gravity 1,025 we require, as I have already said, 

 as large a proportion as about i-i,oooth instead of i-ioo,oooth. 



When the albumen is small in amount, less corrosive sublimate proves 

 efficient. Thus, in a case of spermatocele, where the specific gravity of the 

 fluid was exceedingly low — only 1,007 — I found that i-i,oooth, just intermediate 

 between the proportions required for blood-serum and water, was efficacious. 

 On the other hand, when blood-corpuscles are mixed with the serum in the same 

 amount as in the circulating blood, making the albuminoid substances much more 

 abundant than in serum, we require proportionately more of the corrosive 

 sublimate ; at least i to 500 is required for the purpose of preventing develop- 

 ment. This is a most important consideration after an operation. In the first 

 twenty-four hours the discharge contains a large amount of blood-corpuscles as 

 well as the serum ; whilst, at the same time, it is the most copious — more copious 

 than it will be in any subsequent day, provided all goes well aseptically. It is 

 therefore, an exceedingly serious consideration that in the first twenty-four 

 hours we have a discharge which in both these respects tests our antiseptic 

 more severely than it will ever be tested again, both from its abundance and 

 from its quality. Still, the sal alembroth, whether used with blood-serum or 

 with a normal mixture of serum and corpuscles such as that obtained by 



