GEOLOGY. 



upon by air and water, heat, &c. broken into 

 fragments, or worn down into grains, out of 

 which new strata were formed. Even the newer 

 secondary rocks, since their consolidation, have 

 been subject to great changes, of which very dis 

 tinct monuments remain. Thus, we have single 

 mountains which, from their structure, can be 

 considered only as remnants of great formations, 

 or of great continents no longer in existence. 

 Mount Meisner, in Hesse, six miles long and 

 three broad, rises about 1800 feet above its bas, 

 and 2100 above the sea, overtopping all the 

 neighbouring hills from 40 to 50 miles round. 

 The lowest part of the mountain consists of the 

 same shell, limestone, and sandstone, which 

 exist in the adjacent country. Above these 

 are, first, a bed of sand, then a bed of fossil 

 wood, 100 feet thick at some points, and the 

 whole is covered by a mass of basalt, 500 feet in 

 height. On considering these facts, it is impos 

 sible to avoid concluding, that this mountain 

 which now overtops the neighbouring country, 

 occupied at one time, the bottom of a cavity in 

 the midst of higher lands. The vast mass of 

 fossil wood could not all have grown there, but 

 must have been transported by water from a 

 more elevated surface, and lodged in what was 

 then a hollow. The basalt which covers the 

 wood must also have flowed in a current from a 

 higher site; but the soil over which both the 

 wood and the basalt passed, has been swept 

 away leaving this mountain as a solitary memo 

 rial to attest its existence. Thus, also, on the 

 side of Mount Jura next the Alps, where no 

 other mountain interposes, there are found vast 

 blocks of granite (some of 1000 cubic yards) at 

 the height of more than 2000 feet above the lake 

 of Geneva. These blocks are foreign to the 

 rocks among which they lie, and have evidently 

 come from the opposite chain of the Alps ; but 

 the land which constituted the inclined plane 

 over which they were rolled or transported, has 

 been worn away, and the valley of lower Swit 

 zerland, with its lakes, now occupies its place. 

 Transported masses of primitive rocks, of the 

 same description, are found scattered over the 

 north of Germany, which Van Buch ascertained 

 by their characters to belong to the mountains of 

 Scandinavia ; and which, therefore, carry us 

 back to a period when an elevated continent, 

 occupying the basin of the Baltic, connected 

 Saxony with Norway. S-upp. to Ency. Brit. 

 vol.6. 



The production of a bed for vegetation is ef 

 fected by the decomposition of rocks. This de 

 composition is effected by the expansion of water 

 in the pores or fissures of rocks, by heat or con 

 gelation by the solvent power of moisture and 



%y electricity, which is known to be a powerful 

 Agent of decomposition. As soon as the rock 

 begins to be softened, the seeds of lichens, which 

 are constantly flouting in the air, make it their 



resting place. Their generations occupy it till 

 a finely divided earth is formed, which becomes 

 capable of supporting mosses and heath ; acted 

 upon by light and heat, these plants imbibe the 

 dew, and convert constituent parts of the air 

 into nourishment. Their death and decay afford 

 food for a more perfect species of vegetable ; and, 

 at length, a mould is formed, in which even the 

 trees of the forest can fix their roots, and which 

 is capable of rewarding the labours of the culti 

 vator. The decomposition of rocks tends to the 

 renovation of soils, as well as their cultivation. 

 Finely divided matter is carried by rivers from 

 the higher districts to the low countries, and al 

 luvial lands are usually extremely fertile. By 

 these operations, the quantity of habitable sur 

 face is constantly increased 5 precipitous cliffs 

 are generally made gentle slopes, lakes are filled 

 up, and islands are formed at the mouths of great 

 rivers ; so that as the world grows older, its ca 

 pacity for containing an increased number of in 

 habitants is gradually enlarging. 



Of all the memorials of the past history of our 

 globe, the most interesting are those myriads of 

 remains of organized bodies which exist in the 

 interior of its outer crusts. In these, we find 

 traces of innumerable orders of beings existing 

 under different circumstances, succeeding one 

 another at distant epochs, and varying through 

 multiplied changes of form. &quot; If we examine 

 the secondary rocks, beginning with the most 

 ancient, the first organic remains which present 

 themselves, are those of aquatic plants and large 

 reeds, but of species different from ours. To 

 these succeed madrepores, encrenities, and other 

 aquatic zoophites, living beings of the simplest 

 forms, which remain attached to one spot, and 

 partake, in some degree, of the nature of vege 

 tables. Posterior to these, are ammonites, and 

 other mollusci, still very simple in their forms, 

 and entirely different from any animals now 

 known. After these, some fishes appear ; and 

 plants, consisting of bamboos and ferns, increase, 

 but still different from those which exist. In the 

 next period, along with an increasing number of 

 extinct species of shells and fishes, we meet with 

 amphibious and viviparous quadrupeds, such as 

 crocodiles and tortoises, and some reptiles, as 

 serpents, which show that dry land now existed. 

 As we approach the newest of the solid rock 

 formations, we find lamantins, phocjB, and other 

 cetaceous and mamrniferous sea animals, with 

 some birds. And in the newest of these for 

 mations, we find the remains of herbiferous land 

 animals of extinct species, the paleotherium, 

 anaplotherium, &c. and of birds, with some fresh 

 water shells. In the lowest beds of loose soil, 

 and in peat bogs, are found the remains of the 

 elephant, rhinoceros, hippopotamus, elk, &c. of 

 different species from those which now exist, but 

 belonging to the same genera. Lastly, the bones 

 of the species which are apparently the same 



