44 Gneiss, Old Theory. 



at the base of all the ordinary strata. From the pecu- 

 liarity of the minute contortions in the gneissic rocks, a 

 theory now known to be erroneous was developed, which 

 was this : 



It is frequently found that granite and granitic rocks 

 are intimately associated with gneiss. Thus we often 

 find masses and veins of granite, with gneiss upon their 

 flanks bent in a number of small wavy folds or contor- 

 tions. Granite is a crystalline rock, composed of fel- 

 spar, quartz, and mica, and the old theory (so far true) 

 was that the world at one time was in a state of perfect 

 igneous fusion ; but by and by, when it began to cool, 

 the materials arranged themselves as distinct minerals, 

 according to their different chemical affinities, and 

 consolidated as granite. The great globe was thus 

 composed entirely of granite at the surface ; and by and 

 by, as cooling still progressed, and water, by condensation, 

 attempted to settle on the surface which still remained 

 intensely heated, the water could not lie upon it, for 

 it was constantly being evaporated into the atmosphere ; 

 but when the cooling became more decided, and con- 

 solidation had fairly been established, then water was 

 able to settle on the surface of the heated granite. But 

 as yet it could not settle quietly like the present sea : 

 for by reason of strong radiating heat, all the sea was 

 supposed to be kept in a boiling state, playiag upon the 

 granite hills that rose above its surface. The detritus 

 thus worn from the granite by the waves of this primi- 

 tive sea was spread over its bottom; and because the 

 sea was boiling, the sediment did not settle down in the 

 form of regular layers, but became twisted and contorted 

 in the manner common in gneiss. All gneiss, therefore, 

 was conceived to be the original primitive stratified 

 rock of the world. 



