The woodland growth, upon the lower part of the Canadian, consists of cotton-wood, sycamore, white, blue, and black ash, swamp cedar, red elm, coffee tree, yellow wood, sugar tree, box elder, white and black walnut, wild cherry, mulberry, &c. in the river valley; and hickory, white and post oak, black jack, black oak, &c. upon the adjacent uplands. On a progress westward, the most valuable of the timber trees above enumerated disappear, till at length occasional groves of cotton-wood, mingled with mulberry, {233} red elm, and stunted shrubbery of various kinds, constitute the only woodlands of the country. On this occasion, it may be observed, that the cane or reed, the pea-vine, pawpaw, spice-wood, hop-vine, and several other varieties of shrubs and vines common only to rich soils, are no where to be found within this section, or westward of the proposed meridian. The country of the Canadian above that last considered, or that portion of it west of the assumed meridian, appears to be possessed of a soil somewhat richer than the more northerly parts of the section, but exhibits no indications of extraordinary fecundity in any part of it. Proceeding westward, a very gradual change is observable in the apparent fertility of the soil, the surface becoming more sandy and sterile, and the vegetation less vigorous and luxuriant. The bottoms appear to be composed, in many places, almost exclusively of loose sand, exhibiting but few signs of vegetation. Knobs and drifts of sand, driven from the bed of the river by the violence of the wind, are piled in profusion along the margin of the river throughout the greater part of its length. It is remarkable, that these drifts are in many instances covered with grape vines of a scrubby appearance, bearing fruit in the greatest abundance and perfection. The vines grow to various heights, from eighteen inches to four feet, unaccompanied, in some instances, by any other vegetable, and bear a grape of a dark purple or black colour, of a delicious flavour, and of the size of a large pea or common gooseberry. The waters of this section, almost in every part of it, appear to hold in solution a greater or less proportion of common salt and sulphate of magnesia, which, in many instances, render them too brackish or bitter for use. Saline and nitrous efflorescences frequently occur upon the surface, in various parts of the country, and incrustations of salt, of considerable {234} thickness, are to be found in some few places south of the Arkansa river. As to the existence of rock salt in a mineral state some doubts are to be entertained, if the decision is to rest upon the character of the specimens exhibited as proofs of the fact. The several examples of this formation that we have witnessed, are evidently crystalline salt deposited by a regular process of evaporation and crystallization, and formed into concrete masses or crusts upon the surface of the ground.