Continental Monthly , Vol. 5, No. 6, June, 1864. Various

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      As a natural consequence of the drainage of this immense area, the Mississippi receives into its waters a large amount of suspended earthy matter. This, however, does not very strikingly appear on the upper river, its own banks and those of its tributaries being more of a gravelly character and less friable than lower down. The gravity of particles, therefore, worn from the bed and sides of the channel above, unless the current be exceedingly strong, is greater than the buoyant capacity of the water, and falls to the bottom, along which, sometimes, it is forced by the abrasion of the water, until it meets some obstruction, which gathers the particles into shoal formations. This fact causes much inconvenience in the navigation of the upper rivers.

      It is not until we reach the confluence of the streams of Southern Illinois and Missouri, that the sediment of the river becomes striking. Those streams, freighted with the rich loam and vegetable matter of the prairies of the east and west, soon change entirely the appearance of the Mississippi. Above the Missouri, the river is but slightly tinged; and indeed, after that great current enters, for some distance the two run side by side in the same channel, and yet are divided by a very distinct line of demarcation. It is only after the frequent sinuosities of the channel, that the two waters are thrown into each other and fairly blend. The sedimentary condition of the Missouri is so great that drift floating upon its muddy surface, by accretion becomes so heavily laden with earthy matter that it sinks to the bottom. This precipitation of drift has taken place to such an extent, that the bed of the Missouri is in many places completely covered to a great depth by immense fields of logs. Of all the silt thrown into the Mississippi, the Missouri furnishes about one third.

      After receiving the Missouri, next enters the Ohio. The water of this river is less impregnated than the Missouri, though not by any means free from silt. The country through which it flows is mountainous, and the soil hard, and does not afford the same facility of abrasive action as that of the other rivers.

      From the mouth of the Ohio, the Mississippi pursues a course of nearly four hundred miles, when it receives the turbid waters of the White and Arkansas Rivers. In the intervening distance a large number of small currents, more or less largely sedimentary, according to the character of the country through which they run, enter the Mississippi, in the aggregate adding materially to the sediment of the receiving stream. The White and Arkansas carry in their waters a large amount of unprecipitated matter. In this vicinity, too, sets in that singular system of natural safeguards of the surrounding country, the bayous. The country here also changes its appearance, becoming flat and swampy, and in some parts attaining but a few feet above the flood of the river, whereas in other parts, as we approach the Gulf, the country is even lower than the river.

      The miasmatic and poisonous water of the Yazoo next enters, about ten miles above Vicksburg. This river is more deeply impregnated with a certain kind of impurities than any other tributary of the Mississippi. The waters are green and slimy, and almost sticky with vegetable and animal decomposition. During the hot season the water is certain disease, if taken into the stomach. The name is of Indian origin, and signifies 'River of Death.' The Yazoo receives its supply from bayous and swamps, though it has several considerable tributaries.

      Below the Yazoo, on the west side, enters the Red. The name indicates the peculiar caste of its water. This river carries with it the washings of an extensive area of prairies and swamps, and is the last of the great tributaries. Hence the tendency of streams is directly to the Gulf, and that network of lateral branches, of which we will hereafter speak, begins.

      We have only considered the most prominent tributaries: the sediment also brought down by the numerous smaller streams is very great, and makes great additions to the immense buoyant matter of the Mississippi.

      The river itself from its own banks scours the larger portion of the sediment it contains; and in so gigantic a scale is this carried on, that it can be seen without the exercise of any very remarkable powers of sight. It is not by the imperceptible degrees usually at work in other streams, but often involves in its execution many acres of adjoining land. It will be interesting to consider this more fully.

      By a curious freak of nature, the tendency of the channel of the Mississippi is always toward one or the other of its banks, being influenced by the direction of its bends. The principle is one of nicely regulated refraction. If the river were perfectly straight, the gravity and inertia of its waters would move in a right line, with a velocity beyond all control. But we find the river very sinuous, and the momentum of current consequently lessened. For example, striking in an arm of the river, by the inertia of the moving volume, the water is thrown, and with less velocity, upon the opposite bank, which it pursues until it meets another repellent obstacle, from which it refracts, taking direction again for the other side. Above the Missouri, the river is principally directed by the natural trough of the valley. Below this, however, the channel is purely the work of the river itself, shaped according to the necessities of sudden changes or obstructions. This is proven by the large number of old and dry beds of the river frequently met with, the channel having been diverted in a new direction by the accumulation of sediment and drift which it had not the momentum to force out.

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