PROPHYLAXIS OF MALARIA. 
67 
requisite number of men. If the post is a small one the work can 
be easily accomplished by a sergeant and one or two men, but if the 
area to be covered is large and the buildings are numerous the post 
should be divided into districts, each district being looked after bv 
one man, under the supervision of the sanitary officer and the ser¬ 
geant. Where native barrios or villages have to be sanitated it will 
be necessary, of course, to increase the number of men, but the same 
general plan of organization should be followed. 
Destruction of the adult mosquito .—The adult mosquito may be 
destroyed by various chemicals or they may be caught in mosquito 
traps or by hand. In the military service the methods of destroying 
adult mosquitoes that can be adopted are in general too uncertain 
to be of much value except in fumigating quarters that are to be oc¬ 
cupied by troops in countries where malaria is endemic or upon 
transports plying between malarial and nonmalarial localities. In 
the field the adult mosquito is most easily avoided by methods which 
prevent biting and which are much more practical in application 
than attempts to destroy the insects, although smudges, hereafter 
described, may prove useful in isolated instances. 
A large number of chemicals have been recommended for the de¬ 
struction of adult anophelines, the most important of which will be 
briefly discussed. 
Sulphur dioxide .—Where it is desired to kill the mosquitoes in 
quarters or barracks, in transports or other vessels used for military 
purposes, or in habitations in malarial localities, sulphur dioxide is 
the most valuable agent that we possess. The success attending its 
use in Cuba, Panama, and in Rio cle Janeiro in the fumigation of 
houses, and, indeed, whole blocks of houses, as at Santiago, against 
the yellow-fever mosquito, is familiar to all sanitarians, and the 
same methods used against yellow fever should be employed in the 
case of malaria where the disease is of pernicious type and rapidly 
spreading among troops in quarters. 
In employing this agent it should be remembered that it injures 
most metallic substances and fabrics, and these should be removed 
before fumigation is begun. The methods of fumigation with sul¬ 
phur are well known to all sanitary officers of the Army and will not 
be detailed here. A good rule for determining the amount of sulphur 
necessary to destroy the mosquitoes in fumigation upon a large scale 
is to divide the number of cubic feet in each room of the building by 
500 and reading the result in pounds. Thus, a room 40 feet long. 
20 feet wide, and 12 feet high would contain 9,600 cubic feet, and 
this divided by 500 would give 19.2 pounds of sulphur for such a 
room. 
In the case of malaria it is evident that only in rare instances 
would this method of prophylaxis be used in the military service, 
