GEOLOGICAL FEATURES OF OUR GLOBE. 
491 
not also deposit tlie matter of which they are composed, and 
however inappreciable the substance of a single solar beam 
may be, still in the continued flood of them which has ever 
been pouring upon the globe, have we not a sufficient cause 
assigned for the vast accumulation of untold ages ? may 
not solar light draw forth life, and impart matter to clothe 
it with form, and thus be the grand agent Divine Wisdom 
has appointed to carry on the work of progression through- 
out the wide range of nature ? We know not from what 
remote periods that influence may have been exercised, or 
to what extent ; commensurate perhaps with the solar system 
itself, but we see what an addition the earth has received, 
many of the strata it is true have become so altered by heat 
as almost to pass for a portion of the primitive crust, but 
the metamorphic rocks, however changed, still betray their 
original fossiliferous origin, though appearing to be crys- 
taline, and the same may be said of the gneiss rocks. The 
fossilization of substances is also calculated to give an erro- 
neous idea of age ; pure agatized wood may have no age at 
all, and originate in heat and permeation of gases, which 
only require a brief period to effect the change. 
Perhaps the earliest fossil substance is that of the conferva 
which is found in all but boiling pools, and was first formed 
when they existed on the surface of the earth's earliest and 
still naked pavement, this is seen in the Mocha stone ; the 
same process may still be going on wherever volcanic agency 
prevails, it is thus that fossilized trees in Australia are found 
with agatized roots and woody stems. 
The lasting proofs of the various convulsions which have 
shattered the earth during the different epochs of its ex- 
istence, and which are still apparent on its surface, may be 
summed up in its mountain ranges and islands which have 
either been severed from, or survived the continents of which 
they once formed a part. 
In the northern hemisphere the grounded icebergs and 
thickly strown remains of the mammoth on the Tundra, 
the vast timber mounds on the Polar Islands, the erratic 
blocks and grooved mountains of Britain ; the arid plains 
