My views concerning the geographical range of plants, and the mean degree of temperature requisite for certain kinds of cultivation, had early led me to entertain considerable doubts as to the continuity of a great Tartarian plateau between the Himalaya and the Altai. Writers continued to characterise this plateau as it had been described by Hippocrates (De Ære et Aquis, § xcvi. p. 74), as “the high and naked plains of Scythia, which, without being crowned with mountains, rise and extend to beneath the constellation of the Bear.” Klaproth has the undeniable merit of having been the first to make us acquainted with the true position, extent, and direction of two great and entirely distinct chains of mountains--the Kuen-lün and the Thian-schan, in a part of Asia which is better entitled to the name of “central” than Kashmeer, Baltistan, and the Sacred Lakes of Thibet, (the Manasa and the Ravanahrada). The importance of the Celestial Mountains, the Thian-schan, had indeed been already surmised by Pallas, without his being aware of their volcanic nature; but this highly-gifted investigator of nature, hampered by the then prevailing hypothesis of a dogmatic and fantastic geology, firmly believing in “chains of mountains radiating from a centre,” saw in the Bogdo Oola (the Mons Augustus, or culminating point of the Thian-schan) such a “central node, from whence all the Asiatic mountain chains diverge in rays, and which dominates over all the rest of the continent!” The erroneous idea of a single vast elevated plain occupying the whole of central Asia, the “Plateau de la Tartarie,” took its rise in France, in the latter half of the 18th century. It was the result of historical combinations, and of a not sufficiently attentive study of the writings of the celebrated Venetian traveller, as well as of the naïve relations of those diplomatic monks who, in the 13th and 14th centuries, (thanks to the unity and extent of the Mogul empire at that time) were able to traverse almost the whole of the interior of the continent, from the ports of Syria and of the Caspian Sea to the shores of the Pacific on the east coast of China. If a more exact acquaintance with the language and ancient literature of India had dated farther back among us than half a century, the hypothesis of this central plateau, occupying the wide space between the Himalaya and the south of Siberia, would no doubt have had adduced in its support an ancient and venerable authority from that source. The poem of the Mahabharata appears, in the geographical fragment Bhischmakanda, to describe “Meru” not so much as a mountain as an enormous elevation of the land, which supplies with water at once the sources of the Ganges, those of the Bhadrasoma (Irtysh), and those of the forked Oxus. These physico-geographical views were intermingled in Europe with ideas of other kinds, and with mythical reveries relating to the origin of mankind. It was said that