248 THOMPSON YATES LABORATORIES REPORT 
very doubtful whether, by the cultivation of a habit, the former is of any value. 
Furthermore, it is even questionable whether, in many cases, a larger dose (fifteen 
grains) at intervals as suggested, has not deleterious effects when taken when in 
apparent health. We have observed startling effects in some cases after a single 
administration to healthy persons of even ten grains. 
B. It is by attacking the definitive host that the best results in the prevention 
of malaria fever have been, up to the present, anticipated. 
I. Prevention of Biting by Anopheles 
(a) Culicifuges and Fumigation. — The many substances which have been put 
forward as culicifuges to be smeared on the exposed parts of the body, or to be used 
as perfumes for the purpose of preventing the bites of mosquitoes, are not only 
obnoxious in their use but absolutely useless. Moreover, fumigation of premises 
can be of no practical value. The ' wily ' Anopheles deserves its appellation to an 
extent little expected, and such subterfuges as smearing with kerosene, or the use of 
lavender and other substances can have but little effect, while fumigation is more 
likely to expel the European rather than the mosquitoes. 
(J?) The use of mosquito-proof houses and of mosquito curtains. Manson 2 
advises the extensive use of these conveniences, together with a universal dosing with 
quinine for a period for prevention of malarial fever in West Afriea. It is not 
evident, from the report of his suggestions available, whether the use is to be limited 
to Europeans only, or is to be extended to the natives ; if the latter case, then the 
scheme is evidently impracticable, and if the former it is inefficient. 
The mosquito curtain is astonishingly misused by Europeans on the West 
Coast of Africa. We very rarely met with one who used the curtains in a careful and 
proper manner. Almost all are so placed as to hang outside the bedposts and reach 
on to the ground, being either free or weighted. This is an improper way of hang- 
ing the curtains, which thus act as a trap for those mosquitoes which have taken 
shelter during the day-time under the bed — as very commonly happens. The 
majority of the nets were sometimes so torn as to be of no protective use whatever, 
others had a few holes. All these were practically useless — the persistent Anopheles 
will discover the smallest hole capable of affording its body admission in the search 
for blood. It was common to hear considerable surprise expressed at the presence of 
gorged mosquitoes inside these nets regularly every morning. 
Further, it is hardly to be expected that persons who neglect the proper use 
of the simple mosquito curtain, will attend to the nets at the doors and windows of 
a mosquito-proof house. In fact, we met with such a house in a district where 
mosquitoes were very numerous, and found the nets in a condition very similar to 
that of the mosquito curtains. Apart from the impediment to ventilation which 
would be produced by the use of nets at the doors and windows of a mosquito-proof 
