852 
originally formed and transformed in tlie same way. The 
sandstone has not been formed as the coal has been, nor 
has the ironstone been formed in the same manner as either 
of the other two, nor has the limestone been composed of 
the same materials, or in exactly the same way, as any of the 
other three. The conditions of mineral formation must have 
been different, and even greatly different, in order to the com- 
position of the strata exposed to view. If the observer has 
the opportunity of watching the sinking of the shaft of a deep 
mine, he will * find a variety in the character of the layers 
passed through, corresponding somewhat with the thickness of 
the penetrated mass. Every layer will indicate by its mineral 
character that a peculiar state of things prevailed at the time 
and place of its original formation, or at that of its trans- 
formation afterwards. It was, as we have said, the great 
distinction of Werner to apply this truth to the study of 
geology. His classification of rocks depended on their out- 
ward characters. It was not their chemical distinctions, but 
such as could be detected by the eye or hand, that formed 
the bases of his ideas of them. Jamieson, his great Scottish 
follower, says that chemical science was not then in such a 
state as to warrant dependence on its decisions. He says, 
when speaking of his tour through the Scottish Isles : “ The 
chemical characters which form even the foundation of many 
mineralogical systems, I have seldom employed; from a convic- 
tion that the chemical part of mineralogy, notwithstanding the 
late improvements in the art of analysis, is still to be con- 
sidered as imperfect.” — (See Preface, page viii, Jamieson's 
Mineralogy of the Scottish Isles.)— It was Werner's immensely 
superior acuteness in distinguishing one mineral from another 
by the eye, or hand, or smell, that made him great as a pioneer 
of advanced science, and enabled him to bring a grand truth 
to bear upon the earth's structure. Although his theory of 
the origin of rocks cannot be said to have been at all esta- 
blished, his views of their character will be found to be far 
nearer the truth than those of the men who have all but 
despised them. He was the great champion of the aqueous 
theory as to the formation of almost all strata. 
Hutton opposed this view, with a popularity which shows 
painfully how error may triumph. When this great geologist 
was searching the rocks of the Grampian range, and lighted 
on what he took for veins of injected granite, his joy was 
unbounded. The scientific world may be said to have gone 
after him in the belief of an internal molten state of the globe, 
only to find that it had been misled by a false idea. Yet the 
varied composition of the rocks to which Werner had effec- 
