Many of them have never done service beyond mountain hotel parlors, broad piazzas, and great dining-rooms. They can be bought with “records” complete and shining, and therefore are not as closely related to mountain-climbing as one might suspect them to be. It is refreshing to see young lads stalking about with these alpenstocks and ice-axes, like conquerors amid a subject race. What lofty scorn they have for every man who has not ascended the highest peak, and yet they never dared to try it! They call themselves mountaineers, and at evening and in bad weather stalk and lounge about the hotel, moody, terrible, and statuesque; they speak to none but to other young braves, with whom they perpetually mutter dark things about horrid places and cutting the record. No; good mountaineering is the education of a lifetime begun in childhood, and these pretentious youths are no more mountaineers than their boots are. Under proper precautions, and with an experienced guide, it is glorious and healthful exercise, and for purposes of science has been of incalculable value. In the later Middle Ages invalids came to _Baden_, in the Canton of Aargau, for the sake of the mineral waters; and the springs of _Pfäffers_ were known in 1242, and the waters considered very efficacious, particularly in the case of persons “who had been tortured.” These places are still visited, but the air-cure of the mountain has almost superseded them. Jean Jacques Rousseau expressed surprise that “bathing in the salubrious and beneficial mountain air had not yet become one of the great resources of medical science or of moral education.” There would be no occasion to-day for at least one part of his surprise. The Swiss mountains have developed well-defined and well-known health phases. They have become mediciners, and the snow-clad peaks and the upper snow-clad valleys are being looked to by physicians for the relief of certain ailments not easily remedied by other means. Davos Platz and St. Moritz, in the Engadine, are among the most familiar regions famed for the climatic treatment of disease,--possessing remarkable health-giving properties in lung trouble. It is the exquisite purity of the air, exercise, and especial modes of life which the mountains impose that serve as the chief medicine, and give these heights their beneficial virtues. The rarefaction has its own and special effect. The breathing becomes quicker, deeper, and fuller. One breathes fifteen to twenty-five per cent. less air to produce a given weight of carbonic acid. The action of the air on the blood in the lungs seems to be facilitated with decreasing density; one, however, must ascend over two thousand feet before the lighter air-pressure begins to make itself appreciable, but for every one thousand feet additional the difference in the rarefaction becomes of a very marked character. Here the law of “use and disuse of organs” is illustrated in typical fashion,--parts of