WERNERIAN SYSTEM. 
225 
hus have torn from their place and erupted, rocksk formed in 
he mass below them j and though it were denied, that these 
iubstances are primitive, the difficulty would not be diminished j 
for they are certainly quite unlike any of the Fioetx~trap fa- 
mily, and never could have had a place in that formation and 
to suppose that they were torn from the sides of a subjacent 
mountain on which the volcano rests, is altogether an assum- 
tion as hard to be admitted as the difficulty it is intended to 
remove. 
It becomes, indeed, a question whether Werner was justified Tl>eohsrrva- 
> •. I- r I • L- tions of Wi'V- 
in forming any decisive opinion upon this part of his subject. ,), r 
His own observations upon actually eruptive volcanos appear 
not to have been extensive ; and he had never examined the u nsiw. 
regions where extinct ones were said to exist j liis prejudices 
with respect to the latter being, in fact, so strong, that he con- 
tinued, perhaps still continues, to deny their existence in Au- 
vergne, a country which he never saw, in opposition to the 
testimony of the most intelligent observers of different schools, 
and even after some of the most distinguished of his own pupils 
had been compelled to renounce his opinion upon that in- 
structive district ; and as to \o\camc productions, Mr. Jameson 
"expressly says, that too little is yet known about them to enable 
him to describe them*. 
But if the importance of volcanic power, or some analogous objections to 
agent, in the formation of the globe, has been too little at- ‘‘’•r James 
[tended to by Werner, Sir James Hall has assigned to it effects of tlie extend- 
iin the present economy of the mineral kingdom, apparently 
mo less remote from probability ; having gone so far as to infer, 
{from his experiments and observations, the still continued and 
{transferable agency of volcanic heat as a cause of the indura- 
ttion of rocks on successive portions of the interior of the 
(■earth ; and thus with much ingenuity endeavoured to remove 
lone of the strongest objections to the tenets of Dr. Hutton. 
IBut to heat, in any form, as the cause of consolidation, there 
Ihe bottom of which is still at a great height above the sea, is only 
11693 feet deep. 
• Jameson, III, p. 2iS. 
ar« 
