The Mammoth Hot Springs of the Yellowstone Park are not only beautiful in the tangible forms which they present, and the kaleidoscopic combinations of color which they produce, though their seeming crystal clearness is indescribable, but they have also remarkable medicinal virtues which enhance their interest and practical value. It is on this account that the place is gradually becoming a popular sanitarium, drawing patients from long distances at suitable seasons, especially those who suffer from rheumatic affections and skin diseases. Persistent bathing in the waters accomplishes many remarkable cures, if current statements can be credited, and there is ample reason for such a result. The pure air of this altitude must also be of great benefit to invalids generally, but more especially to those suffering from malarial poison and nervous prostration. The chemical properties of each spring are distinctive, most of them having been carefully analyzed, and the invalid is thus enabled to choose the one which is presumably best adapted to his special ailment. Groups of pines, or single trees, find sufficient nutriment in the calcareous deposit to support life, and thus a certain barrenness is robbed of its depressing effect, while the whole is partially framed by densely wooded hills which serve to throw the terraces strongly into the foreground. When we last looked upon the scene the sun was setting amid a canopy of gold and orange hues, as the evening gun of the military encampment in the valley echoed again and again in sonorous tones among the everlasting hills, and died away in the distant gorges of the Yellowstone. A lady visitor who entered the Park at the same time with the author, on the first day of her arrival placed a pine cone in one of the springs near to the hotel. So rapid is the action of the mineral deposit which is constantly going on that at the close of the eighth day the cone was taken from the spring crystallized, as it were, being encrusted with a silicious deposit nearly the sixteenth of an inch in thickness. Branches of fern, acorns, and other objects are treated in a similar manner, often producing very charming and peculiar ornaments which serve as pleasing souvenirs of the traveler’s visit.