234 Scientific Intelligence. 
ness of induction of so clear-sighted a man, at a time when exact 
observations had been so few, he being the first to recognize the 
simultaneous effect of water and heat in the formation of rocks, 
in aR a system which embraces the whole physical system 
of the globe. He established principles eres in 80 far a8 they 
are fundamental, are now universally a . 
Hutton first caught the meaning of i pasetnaet Fa of 
and w 
away. The scarped cliff, the rugged glen, the lowland allan a are 
each undergoing this process of destruction; wherever land rises 
above ocean, there, from mountain-top to sea-shore, degradation is 
continually going on. Here and there, indeed, the débris of the 
hills may be spread out upon the plains; here and there, too, dark 
angular peaks and crags rise as they rose centuries ago, "and seem 
to defy the elements. But these are ise apparent and not real 
exceptions to the universal law, that, so long as a surface of Jand 
is exposed to the atmosphere, it must suffer disintegration and 
removal. 
But Hutton saw, further, that this waste is not equally distrib- 
uted over the whole face of the dry land. He perceived that 
while, owing to the greater or less resistance offered by different 
kinds of rocks, the rate of decay must vary indefinitely, the 
amount of material must necessarily be greatest where the surplus 
water flows off toward the sea, that is, along the channels of the 
streams. Water-courses, he argued, are precisely in the lines 
which water would naturally follow in running down the slope of 
the land from its water-shed to the sea, and which, when once se 
lected by the surplus drainage, would peceeeaniy be eoneune y 
widened and deepened by the erphinas, power of the 
Hence he regarded the streams and ri of a country as cae 
ing the lines which they had aGudlok in odie out of the 
solid land; and thus he arrived at the deduction that valleys pane 
been, inch by inch and foot by foot, dug out of the solid fram 
work of the land by the same natural a agents—rain, frost, Ma 
i still 
ite of = ash b 
2. On the son and Geology o Santo Domingo ; %Y 
WitiiaM Gaps. 260 4to, iho fe From the Trans- 
actions of the American osophical Society, vol. xv.—Mr. Gabb 
