Page:Historic highways of America (Volume 1).djvu/110

106 animal in appearance, the buffalo rolled himself completely over, apparently with more ease than a horse. A buffalo, by rolling over in this manner, often dusted himself in what was known as a "dry wallow."

The buffaloes' licks, which afforded salt, that mineral so necessary to their health, were the foci of all their roads, the favorite spots about which the herds gyrated and between which they were continually passing. So important were these considered when white men first entered the West that every lick was carefully included in all the maps of the first geographers. Filson's map of Kentucky, for instance, made during the Revolutionary period, contains a large number of circles with dots about them which were the signs of "Salt Springs & Licks," all of them being connected, by trails, "some cleared, others not."

The saline materials of these licks are derived from imprisoned sea-water which has been stored away in the strata below the action of surface waters. When these rocks lie nearer the surface than the line of drainage, the saline materials are leached