THE ANTISEPTIC AND GERMICIDAL PROPERTIES OF SOLUTIONS OF 
FORMALDEHYDE AND THEIR ACTION 
UPON TOXINES. 
INTRODUCTION. 
Since the discovery by Loew and Fischer, in 1886, of the germicidal 
action of formic aldehyde, a large amount of work has been done with 
the substance, both as a gas evolved by various means and in the 
watery solution. 
The recent work by McCiintic (1) seems to have established its 
limitations when used as a gas. The great variation in the results of 
various workers in regard to its action as a germicide and antiseptic 
in its watery solution has led me to try to determine its real value. 
The need of an efficient and, at the same time, a safe and comparatively 
cheap disinfectant is great, especially for the disinfection of the excreta- 
of persons sick with infectious diseases. For this purpose the agent 
should be rapid in its action, an efficient deodorant, comparatively 
cheap, and safe to handle. Formic aldehyde in solution, in my opinion,, 
comes nearer to fultilling these conditions than any other agent we 
have at the present time. 
In the minds of the laity, a deodorant is more or less synonymous 
with a germicide, but of course a deodorant may be almost valueless 
as a disinfectant, and. on the other hand, a disinfectant may possess 
but slight deodorizing properties. In the use of an agent for the 
disinfection of excreta, etc., it is important that the person using it 
understands just what is meant when told to disinfect the discharge 
with a 5 per cent solution. It may be understood that a 5 per cent 
solution of the agent is to be added to the discharge, while what is 
realh^ meant is that the agent shall be in the proportion of 5 parts in 
100 of the total volume tmder treatment. Of course it is needless to 
say that there must be a thorough mixture of the agent and of the 
material to be disinfected, and that they must remain in contact a suf- 
ficient length of time for the maximum action of the germicide to be 
exerted. ^Yhile, for example, a 2 per cent solution might kill typhoid 
bacilli in thirty minutes, it might take a 1 per cent solution an hour or 
longer. 
A number of samples of difierent solutions of formic aldehyde were 
analyzed to determine the exact percentage of the aldehyde contained 
( 7 ) 
