IXEFFICIEXCY OF FERROUS SULPHATE AS AX AXTISEPTIC AND GERMICIDE. 
By Allan J. McLaughlin, 
Assistant Surgeon, Public Health and Marine- Hospital Service. 
Ferrous sulphate, green sulphate of iron, green vitriol, or copperas, 
are the various names of a chemical substance that has long been 
used extensively for the disinfection of animal excreta. It has been 
popular among the lait}" because of its cheapness and ease of appli- 
cation as a disinfectant and deodorant for privy vaults, etc. It has 
official recognition in the French army as a disinfectant for latrines. 
The literature upon the subject is scanty and in some instances 
contradictory. 
Chevalier reviewed a paper by Schattenman, read before the Paris 
Academy of Sciences in 1816, in which Schattenman set forth that 2 
or 3 kilograms of ferrous sulphate were necessary to disinfect 100 
liters of fecal matter. He laid stress on the fact that an intimate 
mixture must be made of the fecal matter and ferrous sulphate 
solution. 
Koch found that a 5 per cent solution failed to destroy anthrax 
spores in six daysi 
Miquel classes ferrous sulphate as a moderateh" antiseptic substance. 
A proportion of 1:90 was required to restrain putrefaction. 
Rideal says: 
The sulphates are not perceptibly antiseptic. Those of iron, mercury, and some 
other metals depend for their power on the amount of the base present, and not on 
the acid. 
Berget" sa^^s: 
It [ferrous sulphate] is not a strong disinfectant, but it is serviceable as a deodor- 
ant. It should be used in the proportion of 1 kilogram (dissolved in 10 liters of 
water ) to a cubic meter of the contents of the vault. 
Munson says: 
The properties of ferrous sulphate which render it useful for purposes of disin- 
fection depend upon its tendency to appropriate oxygen and so become converted 
into the ferric sulphate. These qualities, however, must be considered as antiseptic 
rather than disinfectant, since, according to Laveran, the addition of even 5 or 6 
per cent of the salt to fecal matter is unable uniformly to affect the sterilization of 
the latter. Sulphate of iron is used only in solution, the amount of the iron salt to 
be daily employed depending upon the estimated increment of the fresh fecal matter 
rather than upon any particular strength of the solution. Should the contents of the 
latrine be semifluid, the solution of sulphate of iron may with advantage be made 
up with but a small proportion of water, since for efficiency a high proportion of 
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