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existing, particularly granite and flint, or silex, the 
shining atoms of which compose no small part of 
the sandstone rock. 
It is easy to conceive, that, while these deposits were 
taking place in the soft condition, portions of vegetable 
matters might become intermixed ; and that these, with 
the impressions of the feet and other parts of animals 
and unorganized substances, might be preserved by the 
process of desiccation. ‘The agency of internal heat 
may have also been employed in some cases in baking 
and hardening these crusty layers. 
The sandstone rock, though in some places actually 
in a state of formation at the present time, lies in such 
a manner in the earth’s crust as to indicate an im- 
mense antiquity. The age of these beds varies in 
different situations. The sandstone rocks which con- 
tain the greater part of the impressions are called new 
red sandstone, to distinguish them from the old red, 
which is of a greater age. The deposits on Connecti- 
cut River may not be attributed to the action of this 
river, but are of higher antiquity, probably, than the 
river itself, and proceeded from the waves of an ancient 
sea, existing in a state of the surface of the globe very 
‘different from that of the present day. 
In 1834, tracks were discovered near Hildberghau- 
sen in Saxony, to which Prof. Kaup, of Darmstadt, 
