320 AN ADDRESS ON A NEW ANTISEPTIC DRESSING 



Morson & Son, of Southampton Row, kindly undertook to do this, and I have 

 to thank them for the great pains they have taken in carrying out experiments 

 on this subject at my suggestion. Their manager, Mr. Taubman, soon informed 

 me that in his opinion there was exceedingly little mercury in this so-called 

 double cyanide of mercury and zinc. Very little mercury could be got from 

 it on testing in comparison with what would be obtained if it were a true double 

 salt. He asked if I was sure that the cyanide of zinc was not, after all, the 

 thing that was efficacious ! Was the idea of the double cyanide altogether 

 a delusion ? I need not say how much pleased I should have been if such had 

 been the case — if we could have had the cyanide of zinc without any poisonous 

 mercury in it as an antiseptic. The cyanide of zinc was a perfectly definite 

 compound, there could be no mistake about it. I proceeded to make experiments, 

 and I found, indeed, that cyanide of zinc had antiseptic properties. I made, 

 for instance, experiments of this kind : I took a piece of glass tube like that 

 which I hold in my hand, and packed it in two inches of its length with a piece 

 of gauze charged with cyanide of zinc only, and then, holding it vertically, 

 poured serum of horse's blood into it till the gauze was fully moistened ; and 

 then poured more in, till a quantity dropped out from the lower end equal to 

 that which had produced saturation, the upper part of the gauze being thus 

 thoroughly washed with the serum. 



I then inoculated the top of the gauze with a potent septic drop. I had 

 another such tube packed with gauze that had no cyanide of zinc in it, and 

 I inoculated that in the same way after pouring serum upon it. I then put 

 each into a well-fitting stoppered bottle, so as to prevent any evaporation, 

 and placed them in the incubator. At the end of four days I opened the two 

 bottles. That which contained the gauze without the cyanide of zinc stank, 

 and, on taking portions of the gauze from either one end or the other, squeezing 

 them and examining under the microscope the fluid that escaped, there were 

 seen teeming multitudes of bacteria of various sorts. The bottle with the 

 cyanide-of-zinc gauze, on the other hand, had a pure odour of hydrocyanic 

 acid, which this gauze always has when moist. I then examined drops squeezed 

 from both ends, and I found no bacteria in the clear serum that was pressed 

 out, not only from the lower end, but even from the upper end, in the immediate 

 vicinity of the inoculating drop, and where the gauze had been drenched 

 repeatedly with the serum. 



Now that, so far, is a result that no other antiseptic had ever given me. 

 Take iodide of mercury, for example. Comparatively insoluble as it is, if you 

 pour blood-serum upon it in such profusion you wash the iodide of mercury 

 out, and if you inoculate septically the part so washed you induce bacteric 



