COSMICAL GEOLOGY. t6? 



The Neptunist idea that the' solid materials of the earth had 

 originally been held in solution by a primaeval ocean, no longer 

 harmonised with the advance of chemical knowledge. Hence 

 the Neo-Neptunist leader depicted the primitive earth as 

 amorphous in constitution, silicic and carbonic acid having 

 united all the component particles in a pasty mass. The 

 formation of rock-material began with the separation of the 

 silicates. Light and heat developed as crystallisation pro- 

 ceeded. The earth became self-luminous, and "certain effects 

 were produced which have a resemblance to volcanoes." 

 Different kinds 'of rock separated from the primitive 

 amorphous substance, such as granite, syenite, porphyry, 

 gneiss, crystalline schists, greenstone, slates ; and afterwards 

 sandstone, quartziferous sand, clay, and flint. A calcareous 

 series formed contemporaneously with the siliceous rock-series, 

 the calcareous rocks then becoming more strongly developed 

 in proportion as the siliceous rocks were less developed. A car- 

 boniferous series of rocks began with the formation of graphite 

 and anthracite, reached its maximum in the Carboniferous 

 period, and closed in the youngest mountain-ranges with 

 brown-coal and turf. 



Although the theory of Fuchs was so fantastic that it was 

 practically ignored by geologists, it had at least the merit of 

 calling attention to a possible origin of granite, gneiss, schists, 

 etc., in some other way than from a molten magma. Schaf- 

 hautl was one of the few geologists who accepted the theory of 

 the aqueous origin of crystalline rocks, as he had himself 

 succeeded in producing quartz crystals artificially under the 

 action of superheated water. 



Amongst the writers who supported the nebular theory, the 

 French physicist Ampere was one of the most distinguished. 

 In 1833 he published his " Theorie de la Terre " in the Revue 

 des Deux Mondes. Ampere held the view that during the 

 gradual cooling of the earth, the substances arranged them- 

 selves in the succession of their melting-points. Irregularities 

 in the arrangement of the materials were explained by Ampere 

 as a result of chemical processes which caused a rise of 

 temperature, renewed melting and eruption of masses that 

 had already solidified. Ampere further supposed similar 

 chemical processes to be still in progress in the interior of the 

 earth, and to be the chief cause of mountain-making, volcanoes, 

 and earthquakes. 



