Jan. 1, 1903.] THE TROPICAL AGRICULTURIST. 
493 
this be knsw, that nearly all the children on fhe 
Weft Coast of Africa were more or less infected 
by fever. This he conld tell by catching them 
wild, and examining their blood ; as a matter 
of fact they came in Imndieds, offering tiieir 
blood at 1 penny per drop ! and in that of nearly 
all the children the parasites of malaria were 
found. A year or two ago anything more wretched 
than the condition of these children cnnld not 
be conceived, but already a striking improve- 
ment has been effected, and the death-rate 
marvellously lowered, by simply draining and 
filling np stagnant pools, and applying kerosine 
to the margins of lagoons. This chiefly in Free- 
town which, lie sees no reason to doubt, can be 
made as henlthy as any other tropical city. 
Major Koss is very severe ; and justly so, I think, 
on Colonial Governments for their apathy and 
meanness in this matter of sanitation. Ever ready 
to subscribe liberally to imperial displays; 
in a matter which affects the lite of many 
thousands of helpless subjects, they take not the 
remotest interest. At Ligos and Freetown there 
are now employed at the above-mentioned work, 
from 60 to 80 men with two European Superintend- 
ents, but not a sixpence has yet been obtained 
from Government, the whole cost being defrayed 
by a wealthy and generous Scotsman. Yes, 
niy critical friend ; you like to cfickle about the 
"close-fisted Scot"; but we would like to see a 
little more of such generosity from the predomin- 
ant partners ! Major Koss now proceeded to 
describe his initial work undertaken in 
order to prove to himself the truth of Dr. 
Hanson's theories, 
THE DISSECTING OF MOSQUITOES 
he, found to be a very difficult and tedious task, but 
he persevered for month after month, aniidsS many 
discouragements. The object was to ascertain 
if the parasites really existed in the blood of 
these insects. He continued his experiments for 
2i years examining huiidreds of mosquitoes under 
the microscope. At length, at the close of a 
hard day's work, he discovered malaiia germs in 
a new species of mosquito brought to him by an 
assistant. This is the anophcks, the female of 
which— as far as known, is the only species of 
the mosquito conveying malaria. The malaria 
germs pass into the stomach of the mosquito, 
where they develop and make their way into the 
blood and where they disseminate in minute 
thread-like forms, collecting in the glands, 
thence projected through the proboscis into the 
unlucky victims. 
The Major nursed up a family of a few dozen 
Anophele and immediately set to work to experi- 
ment — not only on human being=, but the 
feathered tribe was equally susceptible from a 
bite of the jut female insect. Sparrows ly the 
score, and even crows died of malaria, after a 
single bite ! Now an insect-bite that would kill, 
say, a Colombo crow would, I iTuagine, kill any 
livmg creature. But how is it, if crows be 
really so susceptible of fever, they do not get 
exterminated? Herein lies a 'wrinkle,' the 
ciows sleep in trees or on the top of houses, and 
the anopheles only rise a few feet above tlie 
water in which they breed. The ancient Incas 
must have had an inkling of this, when they 
raised mounds 100 feet high on which to build 
their dwellings, and the Colomho wallah who 
built an upper storey to his bungalow- was wise 
in his generation, though what became of the poor 
uropjiet ia the chamber below ',' 
Major Ross cx:erimented in other directions, 
for instance, he had freshly dug virgin soil from 
malarial localities placed under his bsd, and there 
he slept without any evil ever befalling him. 
Now, in days of ola — indeed, up till 1894— we 
were taught by sage professors that the disturbing 
of the earth in malarial districts set free certain 
gases which freciuently proved fatal. I was 
told so on arriving in Ceylon ; I was told so 
more pointedly in crossing Panama, Now, it 
seems that, like the fable of the Upas tree, this 
superstition is for ever exploded, and for the 
future we must keep our eye on the mo?quito. 
Hitherto I had been disposed to look upon ib 
as a sort of God-send — sent to warn man tliat 
there was decaying vegetation or dangerous 
stagnant water near. Ndw the vile thing has 
been found out ! 
On one point I could not quite follow tlie Major. 
He s^iid that malaria, was always at its worst, 
in ivet districts and during the wei monsoon — 
instancing Lagos with 200 inches — but the reverse 
is our experience in Ceylon, and in Peru. In 
localities where it never rains, the L-ame fever is very 
rife. Another matter on which we require more 
light is : Why certain districts are worse than 
otliers ? Why Kurunegala is worse than Ratna- 
pura? Why Dumbara is worse than Gampola? 
It would, I fear, be hopeless to expect the 
Ceylon Government to spend anythins' on such an 
investigation ; but surely the Colombo Council 
might do a little towards purifying the unsavoury 
margin of your lake ; while even tlie impecunious 
Municipality of Kandy might afford a lew 
gallons of kerosine to apply to the pud;llcs around 
iJogambra. 
4> 
CACAO AND ITS ENEMIES. 
{From a planter.) 
Thanks many for the Hamel-Smith circular re 
Cacao-tree scru'ibing brushes. I will certainly give 
them a trial and order a dozen fo start with, but 
it is a pity he has nob sent you out a sample, [We 
have one brush to show in Observer Office. — Ed. 
T.A.] I believe in keeping bark as clean as pos- 
sible though it is jusb possible some insects may 
be our friends in destroying other pests, etc ? 
Cacao lias had a soaking this year, but this 
glorious sunshine will do a world of good to trees, 
beast and man. Mosquitoes are holding high 
revels and growing to the size of winsed leeches, 
luckily they don't carry lanterns like glow-flies. 
COCOA BUTTER. 
SOME AMERICAN REPORTS FROM THE 
NETHERLANDS AND FRANCE. 
So many of our readers are interested in cocoa 
butter that we reproduce in jiart two American 
Consular Reports on the subject, made at the 
instance of a New York firm, 
U S Consul-General S Listoe, of Rotterdam, 
says : — 
Oocoa butter is a by-prodnct of the mannfactnre 
cf cocoa powder. It ia derived from cocoa beans by 
the following process of manufacture : The beans 
are roasted, separated from the husks and pfronnd ; 
the fluid cocoa, obtained by grinding, is placed ia 
steam-heated byclranlic presses, which brings it nnder 
a pressnre of t)0,000 kilograms (about K!2,tX)0 ponuds) 
by 75 atmospheres, and about 30 kilograms lOO pounds) 
of butter is pressed out of 100 kilograms (220 poaudsj 
