It would appear, from the proceedings of the Berlin Academy of Sciences, that Dr Güssfeldt’s explorations in the central Chilian Argentine Andes extended from November 1882 to March 1883, in the wild and lofty mountain region containing Aconcagua, the most elevated known point of the American continent, which lies between thirty-two and thirty-five degrees south latitude, and is bounded on the east by the Argentine Pampas, and on the west by the Pacific. Much of this journey being through new country, Dr Güssfeldt daily observed the great orographical and landscape features, the glacial conditions above the snow, the character of the vegetation, and the phenomena of rock-weathering. He also undertook the special duty of fixing positions astronomically and taking altitudes; for which purpose he was provided with nineteen instruments. The central Chilian Argentine Andes are sketched by the traveller as two parallel chains, having on the Pacific an outlying coast-range. The western chain is the true water-parting of the Atlantic and Pacific; and the eastern is in many places broken through by the waters rising in the great trough between the two chains, which has no well-defined valley formation, indications of a longitudinal depression being only found at intervals, constantly interrupted by cross ridges. This trough or basin, one hundred and eighty-five miles in length, is very difficult of exploration, and only three months of the year are available for the purpose. The doctor crossed the divide at four points, and obtained altitudes from nine thousand four hundred and ninety-four feet to twenty-two thousand eight hundred and sixty-seven feet, which was reached near the great volcano Aconcagua, not far from the commencement of Valle Hermoso. A most interesting question of the effect of rarefied air at great elevations upon the human frame is dwelt upon by the doctor. He states that he and his assistant attained twenty-one thousand and thirty feet on Aconcagua, and were able to work their scientific instruments at that height, though not in good condition, through anxiety and want of sleep. Their lungs were physically exhausted by the effort of speaking; but there was no flow of blood from nose or ears. He says that the so-called _puna_ can be resisted by mental effort and confidence, the only effect upon a properly trained individual being increased lung-action, and that any one who could work as he did at twenty-one thousand and thirty feet, could reach the top of Aconcagua, where the proportion of oxygen is only 6.2-3 per cent. less than at the former elevation. NATIVE TREATMENT OF DISEASES IN INDIA.