9 
solution of 5 per cent killed the spores of Bacillus subtiUs in the same 
time.*’ 
The disinfecting* solution devised by Dr. C. B. Dudley^* consists of 
a neutral solution of chlorides of copper and zinc and mercuric chlo- 
ride put up in 8 ounce bottles and securely corked. Each bottle con- 
tains 2,d00 grains of zinc chloride, 120 grains of cupric chloride, 10.5- 
grains of mercuric chloride, and 10 drops of an equal mixture of 
terbene and spirits of turpentine. According to Sedgwick,^ who 
examined it for its e^licienc 3 ^ the chloride of copper is added to fix the 
sulphureted hydrogen and the zinc chloride on account of its deodor- 
izing properties. Sedgwick found the disinfectant an efficient germi- 
cide, killing the spores of B. suhtilis and B. anthracis in a few minutes, 
but did not observe that the zinc chloride materially contributes to its 
value as a disinfectant. 
Sternberg^ states that solutions of chloride of zinc are largelv used 
in this country and in Europe for disinfecting purposes. It is an 
excellent antiseptic and deodorant, but its power to destroy disease 
germs has been very much overestimated. It may, however, be relied 
upon for the destruction of pathogenic organisms, in the absence of 
spores, in solutions which contain from 5 to 10 per cent of the salt. 
On page 20 of the same essav he further states that •‘chloride of zinc 
in 10 per cent solution may be used to disinfect the dejecta of those 
sick with cholera or typhoid fever, or sulphate of copper in a solution 
of the same strength (10 per cent), the amount of the solution used 
being equal to the amount of material to be disinfected.” 
Under the name of •’Burnettls disinfecting fluid” chloride of zinc 
has had an extensive use in England. This fluid contains froin 40 to 
50 per cent of zinc chloride. 
In Belgium infected clothes are boiled in a solution or a mixture of 
240 grams of zinc sulphate and 120 grams of salt dissolved in a pail of 
water. ^ 
The diversit}^ of opinion and results of investigators concerning the 
value of chloride of zinc as a disinfectant is apparent, and it was for 
the purpose of determining the real merits of chloride of zinc as a 
deodorant, antiseptic, and germicide that this work was undertaken. 
Achnoideclgment. — To Dr. M. J. Rosenau, Director of the Hygienic 
Laboratory, I am gratefully indebted for assistance and suggestions 
in the performance of this work. 
R. R. specifications for disinfectant Xo. 27. 
Technology quarterly, v. 6 (2), July, 1893. 
^Sternberg: Lomb Prize Essay — Disinfection and individual prophylaxis against 
infectious diseases, p. 19. Revised edition, 1899. 
f^Rideal: Disinfection and preservation of foods, 1903. 
^Rideal: Disinfection and preservation of food, 1903, p. 345. 
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