34 IOWA ACADEMY OF SCIENCES. 



first, that originally the ocean was as deep as the tallest 

 mountains are high, and that all rock we call igneous or 

 primary, including granites, gneiss and basalt, were due to 

 chemical precipitation from water. Later rocks, including 

 some shales and limestone, were due chiefly to precipitation, 

 but partly to sediment; and lastly, rocks formed chiefly of sed- 

 iment, including upper limestone, sandstone, coal, clays, loam, 

 etc. During this time the universal ocean continually sub- 

 sided, but where the water went to was never explained. He 

 seems to have had no conception of subsidence or elevation of 

 the land. Secondly, he held that there were universal for- 

 mations represented by those of Saxony, extending over the 

 whole earth. When he announced his theory he had never 

 been out of Saxony. It was, according to him, the province of 

 Geology, or "Geognosy" in his nomenclature, to recognize these 

 formations, and hence to predict the location of minerals in other 

 lands. Werner regarded volcanoes as local phenomena of 

 recent origin, and caused by the combustion of coal. Accord- 

 ing to him, veins of whatever kind were due to deposits from 

 the quiescent water in cavities or cracks in the rock. 



Such was the system that remained predominant until the 

 early years of this century. Its overthrow was due to several 

 causes, among which were the influence of Hutton in England, 

 the impossibility of compressing the formations of other lands, 

 when studied by Werner's pupils, within the "universal forma- 

 tions," and the demonstration of the volcanic origin of basalt. 

 The last was due chiefly to Desmorest, as the result of thirty 

 years' work with the region of extinct volcanoes at Auvergne, 

 France, as a center. His complete account of this region was 

 not published until after the beginning of the century. His 

 conclusions were confirmed by two of Werner's most eminent 

 pupils, VonBuch and D'Aubuisson, who investigated the same 

 region between 1802 and 1804 and publicly announced their 

 change of view. 



James Hutton, in 1783-1795, deserves to be called the founder 

 of dynamic geology, though his theory had little influence until 

 explained by Playfair and Hall in 1802. Hutton insisted upon 

 accounting for geological conditions upon the basis of known 

 causes. He studied erosion and advanced the idea that our 

 present world is built up from the fragments of an older world, 

 and perhaps that from one still more ancient. He said, "In 

 the economy of nature I can find no trace of a beginning and no 



