NOTE ON THE DOUBLE CYANIDE OE MERCURY 

 AND ZINC AS AN ANTISEPTIC DRESSING 



Contributed by I.ord Lister to Sir Hector Cameron's Dr. James Watson Lectures, Glasgow, 1907. 

 [British Medical Journal, 1907, vol. i, p. 795. Together with a later Note. J 



I HAVE often regretted that the double cyanide of mercury and zinc is not 

 more generally emplo^^ed, especially in foreign countries. This is, I feel sure, 

 due to want of accjuaintance with it, and I avail myself of the opportunitv 

 kindly afforded me by Sir Hector Cameron of sajdng a few words here regarding 

 its nature, mode of preparation, and use. 



Professor Dunstan, of the Imperial Institute, who most kindlv undertook to 

 investigate its composition, found it to be a double salt of verv unusual t\'pe, 

 being a tetrazincic monomercuric decacyanide, Zn^Hg(CN),o. Its insolubility 

 in water appears to be also a very unusual feature in a double salt.^ 



Messrs. T. Morson and Son (of Elm Street, Gray's Inn Road, London, W.C), 

 to whom I am much indebted for the great pains they have taken in the prepara- 

 tion of the salt, have given me for publication the following formula : — 



Pot. cyanid. 98 per cent 46 parts. 



Hydrarg. cyanid 88 ,, 



Dissolve in water 240 ,, 



Zinc, sulphat 102 



Dissolve in water 120 



When the solutions are cooled to about 60° Fahr., mix, collect the precipitate, 

 and wash until no precipitate occurs with amnion, sulphid. 



The white powder so obtained is dyed with rosalane, J oz. being used to 

 colour 4 lb. of the powder. 



I tried various aniline and other d3^es, and found none that answered its 

 purpose in all respects so perfectly as purified rosalane (as supplied by Messrs. 

 Meister, Lucius, and Briining, of Hoechst-on-Main). Its principal object is to 

 attach the cyanide to a fabric charged with it. and this it does with absolute 

 security. At the same time the colour which it imparts to the white powder 

 has the important effect of indicating the presence and distribution (^f the salt 

 in the fabric. 



' Sec Journal of the Chemical Society for i Sg2. 



LISTER U Z 



