MALARIA. ; 615 
the former because one of the factors in its production is removed, and the 
latter because an excess of water either absorbs or prevents the dissemination of 
the poison. It follows also that high latitudes and high geographical elevations 
are less affected than the low, the other factor, of heat, being to a greater or less 
extent eliminated. 
Stirring up soil that had previously been considered innocuous has in many 
cases, notably in parts of New York City, produced malaria from the exposure to 
sunlight and air of earth loaded with wet and effete matter; and, in the same 
way, withdrawing the water from lakes and ponds and its lowering in rivers give 
rise to similar results. 
The noxious element gets into the atmosphere from direct contiguity, by 
wind currents, and by water courses in which it is carried, if not in solution at 
least in mechanical union, from one point to another. 
Strictly speaking it is neither infectious nor contagious, and only produces 
its evil effects when taken into the body directly. It gains its access here chiefly 
through the respiratory process, though drinking water contaminated with it, or 
bathing in the same gives it some additional means of entrance. 
When a person lives constantly in malaria or its neighborhood, especially if 
it be rich in miasm, disease is pretty sure to follow. Often, indeed, and perhaps 
usually, the trouble takes the form of some of the malarial diseases, so-called, 
whose chief characteristic symptom is a periodic disturbance of the heat-producing 
and regulating function. But it is a mistake to suppose that if this does not 
occur the system has become inured to miasm and tolerant of it. The whole 
constitution is more or less weakened and is rendered more easily a prey to every 
form of ailment; and when a sickness does come, if indeed it does not at once, 
no matter what its name or class, assume the malarial periodicity, it will give 
evidence by its greater virulence and: obstinacy, of the evil influence that has 
gone before. Convalescence from even slight illnesses becomes slow and subject 
to relapses, and the appropriate remedies in such cases are found to be inefficient 
until fortified by the specific—and if any drug deserves the name, it does for 
malarial infection—quinine. 
Woodlands are much more free from miasm than open country. This is 
doubtless due in a great measure to the drainage which the roots of large or 
thickly growing trees keep up, and possibly to the absorbing action of their 
foliage. The fall, too, the season when all verdure is dead or dying, and hence 
less actively engaged in its process of respiration, is the time when this poison 
is most prevalent. Doubtless also the mechanical action of foliage is a factor in 
the protective influence of trees, since a widespread shade must tend to hinder 
the formation of the evil principle and retard its diffusion. Night is more dan- 
gerous than day, since then the earth radiates the heat absorbed during the hours 
of light and with it sends forth its pestilential child. 
Now, while no thinking person will undertake the care of his health without 
the advice of his medical man, when it is once clearly broken by this or any 
