Kara Korourm Padichah, which takes a north-westerly direction, consequently to the north of Ladak, towards the Thsoung ling; the snowy mountains of Hor (Hhor), and of Zzang which thread to the east. Those of Hor, at their north-western extremity, join the Kuen-lun, and in the east take the direction of the Tengri noor (lake of heaven). The Zzang, more southerly than the chain of Hor, borders the long valley of Zzangbo, and goes from the west to the east, towards the Nien tsin tangla gangri, a very high summit which, between H' lassa and lake Tengri noor (improperly called Terkiri), terminates at the mountain Nomchoun oubachi. Between the meridians of Gorkha Katmandhu and H'lassa, the Himma-leh sends to the north towards the right bank or southern border of the valley of Zzangbo several branches covered with perpetual snow. highest is the Yarla Chamboi gangri, of which the name in Thibetian signifies the snowy mountain in the country of God, existing by itself. This summit is to the east of lake Yamrouk Youmdzo, which is called on the maps Paltét, and which resembles a ring, from the presence of an island which fills up almost its whole extent.

The

De Humboldt traces the system of the Himma-leh far beyond the English territory in Hindoostan by means of the writings of the Chinese collected by Klaproth. It borders Assam to the north, contains the sources of the Brahmapoutra, passes by the northern part of Ava, and penetrates into the Yun-nan, a province of China; it exhibits to the west of Young_tchang sharp and snowy summits. It turns abruptly to the north-east on the borders of the Hon Kouang, of the Kiang Si, and of the Fou Kian, and it advances with snowy summits into the

• Klaproth, Memoires relatifs a l' Asie.

vicinity of the ocean, where we find, as a prolongation of the chain, an island (Formosa) whose mountains are covered with snow during the greater part of summer, which indicates an elevation of at least 1,900 toises. Thus the system of Himma-leh may be followed as a continuous chain, from the Eastern Ocean, by the Hindou Khoosh across Kandahar and Khorassan, lastly, to beyond the Caspian Sea into the Adzerbardgan, in an extent of seventythree degrees of longitude, the half of that of the Andes. The western extremity, which is volcanic, and covered with snow at the Demavend, loses the particular characters of the chain in the knot of mountains of Armenia, which attach themselves to the Sangalou, to Bingheul and to Kachmir-dagh, with the lofty summits of the Pachalik of Erzeroum. The mean direction of the system of the Himma-leh is to the north 55° west.

Such are the principal geographical results of the researches of De Humboldt and his companions into the interior of Asia. The remainder which appertain chiefly to natural history and chemistry, are yet to be published, with the exception of two excellent memoirs, the one on the occurrence of the Felis pardus (Cuv.) in the uplands of Asia, the other on the geographical distribution of Infusory animals, by Professor Ehrenberg, and which has made us acquainted with some curious facts regarding the independent existence which these animated corpuscules, so low in the scale of creation, preserve under different climates and local circumstances. The discoveries andconsiderations which belong more immediately to physical geography and to geology, embody some very important facts, among which we may particularly notice the existence of volcanic agency in the central mountain

T. M. p. 291.

are warm.

chain and plains of the old world, and the vast extent which barometrical measurement have now given to the great depression in the south-west of the same continent-circumstances which brought into the direct relation in which they stand with regard to the philosophical views of the origin of the contrasted configurations of the earth's surface, to which geology has given birth, tend at once to give magnitude to these deductions, to confirm them in their application to existing phenomena, and to improve our knowledge of the physical history of the globe.

Active volcanoes De Humboldt regards as the effect of a permanent communication between the interior of the earth in fusion and the atmosphere which envelopes the hardened and oxidated crust of the planet. Beds of lava which issue forth like intermittent springs of liquified earth, and their successive layers, appear to repeat on a small scale before our eyes the formation of crytalline rocks of different ages. Upon the crest of the Cordilleras of the New World, as in the south of Europe and in the west of Asia, an intimate relation may be seen to manifest itself between the chemical action of volcanoes, properly so called, and those which produce rocks, because their form and their position, that is to say, the minimum elevation of their summit, or crater, and the minimum thickness of their flanks (not strengthened by table lands) allow of the issue of earthy matters in fusion, with the salses or mud volcanoes of South America, of Italy, of Taurida, and of the Caspian Sea, first throwing out boulders (large masses of rock) flames and acid vapours; in another stage, and one which has mostly been the subject of descriptions pouring out mud and clay, naptha, and irrespirable gases (hydrogen mixed with carbonic acid and very pure nitrogen.) The action of volcanoes, properly so called, manifests the same relation with the sometimes slow and occasionally rapid formation of beds of gypsum and of an hydrous rock-salt, containing petroleum, condensed hydrogen, sulphuret of iron, and sometimes (at the Rio-Huallaga, to the end of the Andes of Peru) considerable masses of galena, with the origin of thermal springs, with the grouping of metals deposited at different periods from below upwards VOL. I.

(pipe veins) in veins, in isolated or intersecting beds, (Stockwerke) and in the altered rock which neighbours the metalliferous chinks; with earthquakes, whose effects are not always simply dynamic, but which are sometimes accompanied by the chemical phenomena of the development of irrespirable gas, smoke and luminous appearances; lastly, with the upraising either instantaneous or very slow, and only perceived after a long period of time, of some parts of the surface of the globe.

This intimate connexion between so many different phenomena-this mode of viewing volcanic action, as the action of the interior of the globe, on its external crust, or the solid beds which envelope it, has in the present day thrown light upon geognostical and physical problems, which had hitherto appeared inexplicable. The analogy of well-observed facts, the rigorous examination of phenomena, which take place before our eyes, in the different regions of the earth, begin to lead us progressively to guess (not by noting all the conditions, but by contemplating the general modifications) what took place at those distant periods which preceded historical times, Volcanicity, that is to say, the influence which the interior of a planet exerts on its external crust, in the different stages of refrigeration, caused by the dif ference of aggregation (of fluidity and of solidity) of the matters which compose it, this action from within to without, is at the present time much diminished-restrained to a few points

intermittent-less often changing its place-much simplified in its chemical effects, only producing rocks around little circular openings, or upon longitudinal fissures of little extent, and only showing its power at great distances dynamically in shaking the crust of our planet in linear directions, or in circles of simultaneous oscillations which remain the same during a great number of ages. In times which preceded the existence of the human race, the action of the interior of the globe upon the solid crust, which was increasing in volume, has caused the temperature of the atmosphere to be modified and rendered the whole globe habitable to productions which may be looked upon as tropical, since by the effect of radiation and of the cooling of the surface, the relations of the posi

4 D

tion of the earth with a central body (the sun) have begun to determine almost exclusively the diversity of geographical latitudes.

It is also in these primitive times that the elastic fluids, the volcanic forces of the interior perhaps more powerful, and making themselves more easily a passage through the oxidated and solidified crust, have broken that crust, and have injected, not only in veins (dykes) but in masses very irregular in form, matters of a great density (ferruginous basalts, melaphyres, and metallic deposits) matters which have introduced themselves after the solidification and flattening of the earth had taken place. The acceleration which the oscillations of the pendulum undergo on several points of the earth often offer from this geognostical cause deceitful appearances of an increase of elipticity greater than what results from the union of trigonometrical measurements and the theory of lunar inequalities. The epoch of the great geognostic revolutions has been when the communications of the fluid interior of our planet and its atmosphere were most frequent, and acted upon a greater number of points where the tendency to establish these communications caused to be elevated at different ages and in different modes (apparently determined by the diversity of these epochs) upon long fissures, cordilleras as those of the Himma-leh and the Andes, chains of mountains of a lesser elevation and those ridges or crests whose varied undulations embellish the landscape of our plains. It is as if in testimony of these elevations, and marking (according to the extended and ingenious views of M. Elie de Beaumont) the relative age of mountains that De Humboldt mentions the occurrence in the Andes, of the New World at Cundinamarca, of extensive formations of stone stretching from the plains of Magdalena and of Meta almost without interruption upon table lands from fourteen to sixteen hundred toises in height, and still more recently in the north of Asia, in the chain of the Ural, the same bones of antideluvian anmals (so celebrated

in the low regions of Kama and the Irtyche) mingled on the back of the chain in the table lands between Berezovok and Iekaterinbourg, with transported deposits, rich in gold, diamonds, and platinum. It is further in testimony of this subterranean action of elastic fluids which upraise continents, domes, and chains of mountains, which displace rocks and the organic remains which they contain, which form eminences and hollows when the vault gives way or falls in; that we can consider that great depression of the west of Asia, of which the surface of the Caspian Sea and of lake Aral forms the lowest part, 50 and 32 toises beneath the level of the ocean, but which extends, as shewn by the new barometrical measurement made by Messrs. Humboldt, Hofmann, Heffmersen, and Gustavus Rose, in the interior of the country as far as Saratov and Orenbourg upon Jaik, apparently also to the south-east to the lower part of the course of the Sihoun (Jaxartes) and of the Amout (Djihoun, Oxus of the antients). This depression of a considerable portion of Asia; this lowering of a continental mass of more three hundred feet below the surface of the waters of the ocean in their mean state of equilibrium has not hitherto been considered in all its importance, because we were ignorant of the extent of the phenomenon of depression which was presented in a slight degree in some of the littoral countries of Europe and of Egypt. The formation of this great concavity in the surface of the northwest of Asia appears to De Humboldt to be in intimate relation with the upraising of the mountains of the Cancasus, of Hindou-kho, and of the upland of Persia, which border the Caspian Sea and the Maveralnahar to the south, perhaps also more to the east, with the upraising of the great plain, which is designated by the very vague and incorrect term of the upland of Upper Asia; and lastly this concavity of the antient world is proved from the facts collected by De Humboldt on the frontiers of Chinese Dzoungaria between the forts of Oustkamenogorsk