MOUNTAINS AND THEIR ORIGIN. 115 
close of the eighteenth and the opening of the 
nineteenth century. From the general character 
of these rocks, as well as the number of marine 
shells contained in them, he convinced himself 
that the whole series, including the Coal, the 
Tocltliegende , the Kupferschiefer , the Zechstein , the 
Red Sandstone, and the Muschel-Kalk , had been 
deposited under the agency of water, and were 
the work of the ocean. 
Thus far he was right, with the exception that 
he did not include the accumulation of materials 
by the local action of fresh water afterwards 
traced by Cuvier and Brogniart in the Tertiary 
deposits about Paris. But from these data he 
went a step too far, and assumed that all rocks, 
except the modern lavas, must have been accu- 
mulated by the sea, — believing even the gran- 
ites, porphyries, and basalts to have been depos- 
ited in the ocean and crystallized from the sub- 
stances it contained in solution. 
But, in the mean time, James Hutton, a Scotch 
geologist, was looking at phenomena of a like 
character from a very different point of view. 
In the neighborhood of Edinburgh, where he 
lived, was an extensive region of trap-rock,— 
that is, of igneous rock, which had forced itself 
through the stratified deposits, sometimes spread- 
ing in a continuous sheet over large tracts, or 
splitting them open and filling all the interstices 
