when the lands of Ohio, Indiana, and Illinois, can be no longer procured at a low rate.
Those who would go in search of healthy situations may keep in view, that their object can only be attained, at a distance from swamps, and rivers which overflow their banks; it being well known, when the former are dried up, and when the latter recede within their low-water boundaries, vast quantities of mud and vegetable matters are exposed to the heat of the sun, and a rapid decomposition immediately commences. The gaseous constituents evolved give a perceptible taint to the air, and are understood to form the miasmata that occasion agues, bilious fevers, and liver complaints. The best navigable waters, and the most healthy parts of the country, are, in some measure, incompatible, and seldom admitting of immediate proximity to one another. Happily, a moderate height of land is usually sufficient to prevent the accumulation of stagnant waters, and to promote a motion in rivers, that lessens the scope of their inundations, or retains them altogether within their banks. A degree of elevation conducive to a comparatively healthy climate, may be usually found within two or three miles of the river; but as the contaminated air is liable to be transported by winds, and probably not sufficiently diluted with the atmosphere in passing over such small spaces; a greater distance from the source of contagion {163} is no doubt preferable. I have, on various occasions, seen persons from the higher country, about forty miles north of this place, whose complexions are apparently more healthy than those of the people who live on the banks of the Ohio; and several of late who profess to have a reluctance to come down to the river on business, at the present season of the year.
In the preceding part of this letter I mentioned the
