68 
PROPHYLAXIS OF MALARIA. 
owing to the fact that other and more easily applied methods would 
render it unnecessary. However, there is no doubt of its great value 
in the prevention of the transmission of yellow fever and in great 
epidemics of malaria, such as have occurred among troops in 
quarters, it would undoubtedly be of equal value. 
Smudges. —In the field many adult mosquitoes could be destroyed 
by fires made of material producing a dense smoke, as green vegeta¬ 
tion or bark. The American Indian used this method of rendering 
his tent inhabitable and all hunters are familiar with this device, 
which might prove very useful to an army in the field in regions 
where mosquitoes were very numerous and mosquito nets unob¬ 
tainable. 
Pyrethrum powder. —Pyrethrum powder is made from the dried 
flower heads of plants belonging to the genus Chrysanthemum , grow¬ 
ing in Transcaucasia. The powder is more commonly known as 
Persian or Dalmatian insect powder, and depends for its efficiency 
on the presence of certain oleoresins in the dried flowers, so that to 
be efficient the powder must be comparatively fresh. The best prep¬ 
aration for use in this country is made in California and is marketed 
under the proprietary name of “ buhach ” powder. 
For the purpose of destroying mosquitoes the powder is burned in 
a room, being placed upon a dish or tin and a match touched to it, 
when it will burn slowly and give off a large volume of smoke hav¬ 
ing a peculiar odor; or the powder may be procured in the form of 
cones or pastilles and these burned. The smoke is not harmful or 
very unpleasant to most people, and if the powder be burned in a 
closed room it will stupify all mosquitoes in the room and they may 
be swept from the floor and destroyed. The use of this powder in 
the rooms of quarters infested with mosquitoes might be of benefit 
where other measures could not be taken to get rid of them, but from 
a military standpoint this method of destroying mosquitoes possesses 
little value. 
Numerous other fumigants have been recommended for destroying 
adult mosquitoes, as camphor phenol or Mimm’s Culicide, Pyrofume, 
mercuric chloride, powdered stramonium, and formaldehyde gas, 
but none of them are of any importance in the prophylaxis of ma¬ 
laria in the military service and will not be discussed. 
Mosquito catching as a prophylactic method. —The catching of 
adult mosquitoes, first advocated by Orenstein, 30 in the Canal Zone, 
is really deserving of much greater consideration as a prophylactic 
method than it has received. It is a method that could readily be 
adopted in the military service and, under certain conditions, would 
be a most valuable one, especially in temporary camps in the Tropics. 
In his paper, published in 1918, Orenstein states that this method 
has been extensively employed in the Panama Canal Zone and that 
