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Show ~08 INFLUENCE OF MAN' [Ch. XII. . rs and should attempt to • C) d h t followmg yea ' . . . m 178u an t e wo f tl a ocean wherem 1t might . . 1 d st abysses o 1.. ' • • cons1gn 1t to t 1e eepe f dl'ties from which 1t rose m 1 to the pro un approach most near Y . h ds of years before . h mi ht toll for t ousan the volcamc vent, t ey g y h matter borne down by 1' bed et t e their task was accomp IS • • single year, probably G d :Burrampooter, m a the anges an 1 the mass of Icelandic lava exceeds, in weight and vo u~e, produced by that great eruption. CHAPTER XIII. EJrects produced by the action of animal and vegetable life on the material cortstituents of the earth's crust-Imbedding of organic 1·emains in deposits on emerged land-Growth of Peat-Peat abundant in cold and humid climatesSite of many ancient forests in Europe now occupied by peat-Recent date of many of these changes-Sources of Bog Iron-ore-Preservation of animal substances in Peat-Causes of its antiseptic property-Miring of quadrupedsBursting of the Solway Moss-Bones of herbivorous quadrupeds found in peat -Imbedding of animal remains in Caves and Fissures-Formation of borf"y breccias-Human bo~es and pottery intermixed with the remains of extinct quadrupeds in caves in the South of France-Inferences deducible from such associations. WE now come to the second subdivision of the inquiry explained in the preceding chapter,-the consideration of the permanent modifications produced in the material constituents of the earth's crust, by the action of animal and vegetable life. New mineral compounds, such as might never have existed in this globe but for the action of the powers of vitality, are annua1ly formed, and made to enter into deposits accumulated both above and beneath the waters. Although we can neither explain nor imitate the processes of animal and vegetable life whereby those substances are produced, yet we can investigate the laws by virtue of which organic matter becomes imbedded in new strata,-sometimes imparting to them a peculiar mineral composition,-sometimes leaving durable impressions and casts of the forms of animate beings in rocks, so as to modify their structure and appearance. It has been well remarked by M. Constant Prevost, that the effects o~ geological causes are divisible into two great classes; those produced on the surface during the immersion of land beneath the waters, and those which take place after its emersion. Agreeably to this classification we shall consider, first, in what manner animal and vegetable remains become included and preserved in solid deposits on emerged land, or that part Vot.. II. p |