602 
PREVENTION AND PRODUCTION OF MALARIA. 
imitate the methods by which nature prevents it. The warm 
alkaline soil, moistened, and washed with air and water, 
becomes acid, it sends forth less volatile matter—decomposi¬ 
tion is stopped to a great extent, the matter is preserved. 
Cold prevents the action, drainage assists oxidation by a 
more active state of soil. By these modes and others the 
soil is disinfected by nature; when these do not act sufficiently, 
we may use disinfecting agents. By their means decomposi¬ 
tion may be interrupted without fear of diminishing the power 
of the plant to take up food. By the use of disinfecting agents, 
Mr. McDougall had been able to feed sheep and cattle, and 
retain them in health, on meadows constantly wet by irrigation 
with liquid manure. The disinfectant used is from the 
products of the distillation of tar, and the amount required is 
small. Animal life is rapidly destroyed by it, and chemical 
decomposition is stayed. All climates can furnish.this, where 
coal lies or where trees grow. 
u It would be possible to irrigate great districts at a very 
small expense. The result would be as certain on a large 
scale as on a small one; and it is probable that, in some 
cases one or two applications would be sufficient, for a long 
period at least. By the new state of things, destructive 
insects would also be destroyed. Although, according to 
Dr. McCulloch, there are many parts of our own islands 
infected by malaria, most, if not all, can be cured by good 
attention to well-known agricultural maxims. This new 
method is especially applicable to other countries, and to 
more violent stages of the disease. The author hopes to have 
it tried on extensive districts in Italy. The method arose 
out of an advice everywhere neglected, but still cherished as 
true, to disinfect whole cities by beginning with the sewers, 
the origin and reservoir of all the mischief. 
“The author believes that he has shown that decomposition, 
to a most pernicious extent, is possible in soils; that this is 
not a mere opinion, but a fact readily demonstrated; but 
that decomposition may be arrested artificially to the preser¬ 
vation of health without the destruction of vegetation, and 
that in these facts we have not only a surer basis in our 
reasonings on the origin of malaria, but an almost certain 
process for its ultimate and total extermination .”—Chemical 
News. ■ 
