66 
PROPHYLAXIS OF MALARIA. 
The discovery of these small breeding places of mosquitoes and 
their proper treatment forms one of the most important duties of 
sanitary officers in localities where malaria is endemic, and the ability 
to make a really scientific mosquito survey of a post and its surround¬ 
ings should be considered one of the most valuable of all possessions 
to one who is engaged in the prevention of this disease. 
All receptacles in which mosquitoes may breed and which are not 
needed in domestic operations should be removed or destroyed, and 
those in which it is necessary to keep water should either be frequently 
emptied, screened, or oiled. Barrels or tubs for the collection of rain 
water, as well as cisterns, should be covered with well-fitted screen 
covers, made of wire containing not less than 18 meshes to the inch. 
Unused hoppers of toilets and water traps should be flushed thor¬ 
oughly at least once a week, and drains should be frequently inspected 
and flushed. One of the most common sources of mosquitoes con¬ 
nected with barracks and quarters are clogged roof gutters, and I 
have frequently found such a gutter alive with larvae after heavy 
rains that had left the gutter full, followed by enough light rain to 
prevent total evaporation of the water. The inspection of all roof 
gutters and their repair, where clogged, is an important prophylactic 
measure in Army posts. 
The fire buckets found in most barracks are prolific sources of 
mosquitoes unless they are properly looked after. All that is neces¬ 
sary in order to prevent the development of larvae is to see that 
they are emptied each week and filled with fresh water. As the 
average life of the larvae is about 14 days, one is perfectly safe if 
the buckets are emptied each week. If desired, wire screen covers 
may be used, but these are expensive and unnecessary if the buckets 
be properly emptied and refilled at weekly intervals. The oiling of 
the water in fire buckets, so frequently observed, is an evidence of 
the lack of knowledge of the life history of mosquitoes on the part 
of the officer ordering such a procedure, and certainly the addition 
of oil to water destined to extinguish fire does not improve its value 
in that direction. The buckets should not be emptied into the sewer, 
but upon the ground in direct sunlight where the water will quickly 
evaporate and the sun kill any larvae that may be present. 
Water troughs for domestic animals should be flushed frequently, 
and in no case should the water be allowed to remain if the trough 
.is not in use. The tanks in water-closets, the sewer traps of the 
post, and open cesspools, if present, should be frequently inspected 
and properly treated, the tanks and sewer traps by flushing or oiling 
and the cesspools by oiling at intervals of two weeks. 
The best way to accomplish the abolition of the small breeding 
places mentioned is to place the work under the charge of a sani¬ 
tary officer, who should be assisted by a good sergeant and the 
