6 Notice of the Wonders of Geology. 
The fossiliferous formations have assumed a high degree of 
interest in our times, an interest which is constantly increasing 
with the progress of geology. In the earlier periods of the science, 
the primary rocks were the chief objects of investigation, and 
fossil geology, being little cultivated, was little understood. The 
primary rocks were viewed as the types of permanency, the pri- 
mordial foundations laid down in the beginning, and which, as 
was supposed, had rarely been disturbed in the progress of ge- 
ological events. But now we cannot assign a period beyond 
which there has not been change, event, and revolution. Granite 
itself, in the early systems of geology the very personification of 
physical antiquity and stability, is now proved to be of all geo- 
logical ages, anterior to the tertiary ; and it would in no manner 
surprise us, were the progress of discovery to place granite in 
some of its irruptions, above the tertiary, like the ancient lavas 
of Auvergne, many of which repose upon the tertiary of that re- 
markable country. 
The light which has burst in upon us eet the microscopic dis- 
coveries of Ehrenberg, has opened a new world in the mineral 
kingdom; for none would have expected to find minerals and 
rocks Semaposad of the silicified, ferruginous, and calcareous pet- 
rifactions of i les, requiring thousands of mil- 
lions of individuals, to fill the capacity of a cubic inch. 
_ In all probability, we are to proceed in these discoveries from 
flint, opal, chalcedony, agate, tripoli, and beds of sand, and clay, 
and marl, to earlier formations, which also may contain their myri- 
ads of invisible animalcules. Dr. Mantell has presented this sub- 
ject with his usual felicity, and with good figures of many mag- 
nified fossil animalcules; while his remarks evince an expectation 
that even the most ancient rocks may not be exempt from simi- 
lar evanescent fossils. It is, however, not easy to understand 
how any organic body can retain its form in the midst of fusion, 
and although silicified shields of animalecules may be proof, to a 
certain extent, against fire, we cannot suppose that they can re- 
main, with their characteristic forms, in the midst of granite and 
porphyry, while the very quartz sink feldspar, of which they are 
so largely composed, have flowed in igneous fusion, or acquired a 
> by fire so soft and yielding as to admit of crystalliza- 
esricees ate therefore, of traces of animalcules from ig- 
no would not necessarily prove that their materials 
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