their Relation to Disease. 
5 
exposed parts. Some of those which have given the best 
results are :—■ 
(i) Essential oil of oranges, 30 gms.; camphorated alcohol, 
30 gms. ; oil of cedar, 15 gms. 
(ii) Castor oil, alcohol and oil of lavender in equal parts. 
(iii) Essential oil of oranges, 30 gms. ; liquid vaseline, 
120 gms. 
(iv) In military camps, where the essential oils mentioned 
above would be too scarce or expensive to use in large 
quantities, pure kerosene has been found to be efficacious, 
but of course the smell is objectionable. All these sub¬ 
stances are transient in their effects when the climatic 
conditions are such as to cause much perspiration. 
(c) It has often been noticed that some mosquitoes more 
readily attack persons wearing dark clothing. 
DESTRUCTION OF ADULTS. 
Traps. —Large numbers of mosquitoes may sometimes be 
caught by placing suitable traps in cool shady places where they 
are likely to retire during the day. A large box with one end 
open placed among bushes makes a good trap. 
Destruction of Cover. —-Mosquitoes frequently take shelter 
in long grass and other coarse herbage, and if it is practicable to 
burn this the insects will either be destroyed or driven to seek 
shelter elsewhere. 
Sprays. —In temperate regions the females of several species 
pass the winter in a torpid state, remaining on the walls of cellars 
and similar places, and there they may easily be destroyed by 
spraying the walls with some substance poisonous to them. 
Similar methods may also be used against those which “ aestivate ” 
in hot dry countries. • Giemsa recommends either:— 
(i) 2J per cent, solution of potash soap; or 
(ii) A solution of 3 drams of medical soda soap in If pints of 
water containing 11 drams of formalin. The smell of the 
formalin may be removed by allowing ammonia to evaporate. 
A liquid prepared by the Russian scientist, Dr. Malinin, has 
been extensively and successfully used in parts of Caucasia for the 
destruction of mosquitoes in barracks and camps, by spraying on 
