EEVIEWS. 
93 
GEOLOGICAL TEEATISES.-' 
I F Astronomy may be said to stand at the head of the series of philo- 
sophical branches of inquiry, assuredly Geology comes next in order of 
importance. This position is fully justified by the character of the science 
which deals with the past and present history of the globe on which we live. 
It is the office of the geologist to decipher that great “ stone-book ” of nature, 
in whose pages lie wondrous secrets as yet unrevealed to mortals. Hence 
there are very few departments of science whose field of observation is so 
vast, or whose natural laws are fraught with such serious interest as those of 
Geology. This may explain why so many are acquainted with its leading 
principles, and also why so many popular treatises appear upon the subject 
from time to time. As a rule, Ave hail with pleasure the appearance of a 
well-executed popular essay upon any branch of technical knowledge ; but 
Ave feel disjDosed to accord special praise to the man AAdio produces a useful 
and readable work upon matters relating to Geology. 
The first of the treatises noAv under notice is written by no less a personage 
than the President of the Geological Society, and, as we might have expected 
from the author’s high standing in the Geological world, it is as accurate in 
the information it contains as it is readable in point of literary composition. 
It is really a modified report of six lectures delivered to working-men in the 
Eoyal School of Mines in 1863. It opens Avith a chapter on denudation, 
and in this we are shoAvn hoAv constantly the forces of Nature are employed 
in breaking down old rock-formations and developing new ones. The moun- 
tain stream, as it rushes ‘‘ from its rocky bed,” brings with it the debris of 
the surrounding earth, these it pours into the stream, which in its turn 
passes them to the river, and finally they are brought down to the sea, and 
being deposited at the bottom, help to form new rocks, which in future ages 
will be found to contain traces of the animal and vegetable life of the 
present day. But this is not the only illustration of the effects of denuda- 
tion which Professor Eamsay gives his readers. He shows that it is only by 
evoking the assistance of denudation that Ave can explain why certain 
deposits exist in a perfect condition in basins or valleys, Avhilst there is 
hardly a trace of them to be found on the adjoining mountains or hill-sides. 
Originally these deposits were formed all over the surface of the rocks 
composmg the valley and mountain ; but as the latter rose from the 
water, the new formation (let us say of coal, for example) became washed 
away, aiid that in the valley was left to tell the tale. Metamorphisni 
is A^ery lucidly explained. It consists in the change which a stratified or 
“ The Physical Geography and Geology of Great Britain.” By A. C. 
Eamsay, F.E.S., &c. Second edition. Pp. 199. London : Stanford. 1864. 
“ AdA'^anced Text-book of Physical Geography.” By David Paqe, F.E.S.E., 
&c. Pp. 320. Edinburgh and London : BlackAVOod & Sons. 1864. 
“ Physical Geography for Schools and General Eeaders.” By M. F. 
Maury, LL.D., Commander in the NaAy of the Confederate States of 
America. Pp. 141. London : Longman. 1864. 
“ The Physical History of the Earth.” Meditations by A Student. Pp. 
134. London : Bagster. 1864. 
