1888.] Dr Woodhead on Mercitric Salts as AntiseiMcs. 
235 
2. Notes on the Use of Mercuric Salts in Solution as 
Antiseptic Surgical Lotions. By G. Sims Woodhead, 
M.D., RRC.P. Edin. 
Koch, in his article on Disinfection and Antiseptics in the 
Mlttheilungen aus dem K. Gesundheitsamte, vol. i., 1881, p. 264 
(abstracted by Dr Whitelegge in the publications of the New 
Sydenham Society, vol. for 1886, “Microparasites in Disease”), 
gives the result of an elaborate series of experiments with mercuric 
diloride, and comes to the conclusion that a single application of 
a very dilute solution (1 to 1000, or even 1 to 5000) is sufficient 
to destroy the most resistant organism in a few minutes. He 
further states that, “ with longer exposure, it only begins to he 
unreliable when diluted beyond 1 to 20,000.” 
In consequence of Koch’s experiments, corrosive sublimate solu- 
tion was, very rightly, introduced as one of the most valuable, if 
not the most valuable, of all antiseptic lotions in surgical and 
obstetrical practice. 
A most important fact is, however, too frequently ignored — a 
fact on which Koch laid some stress, but one in connection with 
which his argument has not been followed, or has certainly not 
been sufficiently attended to. He points out that, if liquids contain- 
ing albumen or sulphuretted hydrogen, or other substances forming 
insoluble compounds with mercury salts, are to be disinfected, enough 
of the mercuric chloride must be added to leave at least 1 to 5000 
in solution, after all precipitation has ceased. In the disinfection 
of such liquids by means of mercurial salts, it should be remembered 
that precipitates will form, which, if the process is frequently 
repeated, may accumulate, and become dangerous on account of the 
amount of mercury which they contain. 
The following expresses roughly Koch’s results with bichloride of 
mercury, used as a germicide : — 
In solution of I to 1000, it kills anthrax spores in ten minutes, 
and even those spores found in garden earth which are much more 
resistant than anthrax spores. 
1 to 5000 also kills, if allowed to act for a considerable time. 
