94 
POPULAE SCIENCE EEVIEW. 
sedimentary rock undergoes when subject to intense heat and chemical action. 
The simplest kind of metamorphism is when an igneous rock is forced through 
or overflows a stratified rock, and remains for a long time in a melted state, the 
result of which is an alteration of the adjacent portions of the aqueous formation. 
Thus sandstone may, by such a process, be converted into quartz rock, which 
is no longer hewable, like ordinary sandstone, but breaks with a hard and 
splintering ^fracture. The writer concludes his remarks on this subject by 
expressing his opinion that granite is “ simply the result of the extreme of 
metamorphism,” and is not, as some geologists still maintain, of really 
igneous origin. That lake basins were originally scooped out by the opera- 
tion of huge glaciers, is a doctrine to which Professor Eamsay seems also, 
and with much reason, to incline. This is a theory which has only been 
broached of late years, but which has the support of such men as Sir W. 
Logan, Dr. Newberry, Dr. Otto Torrel, Mr. Geikie, Professor Hind ^of 
Toronto, and many others. On the much-debated questions relating to bone 
caves, waste of sea-coast, raised beaches, and contemporaneity of man and 
the mammoth, the author’s comments are most interesting and instructive. 
The volume which Professor Eamsay has presented to the public is illustrated 
by a small but exquisitely coloured geological map of Great Britain, and is 
got up in a manner highly creditable to its publisher. Altogether, it is an 
admkable little work, and we heartily commend it to our readers’ attention. 
Mr. Page’s production relates rather to Physical Geography than to pure 
Geology ; but is, of its kind, a useful and very well arranged treatise. With 
the student Mr. Page has ever been a favourite ; for in his various contribu- 
tions to scientific literature, he has left nothing undone to impress his ideas 
clearly upon the reader’s mind, and by the aid of copious glossaries, notes, 
and recapitulatory chapters, he has cleared away many of those difiiculties 
attending the study of science. The “ Text-book of Physical Geography ” 
does not form an exception to the rule. We observe throughout its pages a 
careful avoidance of that tendency to pile up dry facts, which is so common 
a feature of the style of certain writers. It is to the grand principles of the 
science that Mr. Page devotes himself, and, in our opinion, he has not done 
so to any disadvantage. The paragraphs are full of instructive matter 
agreeably conveyed, and it seems as though each chapter were complete in 
itself ; for the reader can turn to any part of the volume and study profitably, 
although he has not begun his study systematically. In one or two instances 
we have noticed that the book is not as well “ up to date ” as it might have 
been ; but the cases are of such trifling importance that they may very 
readily be forgiven, when we consider the valuable character of the other 
portions of the essay. 
The author of the “ Physical Geography of the Sea ” has sent out a little 
treatise on Physical Geography, which may advantageously be placed in the 
hands of young beginners. It deals with the usual subjects embraced by the 
science of Physical Geography : — seas and ocean currents, rain and rivers, 
winds and tides, seasons and weather, &c. In most cases the writer has been 
very happy, both in his descriptions and illustrations ; but in one or two 
places we find a good deal of clumsiness of expression, which we had scarcely 
anticipated. The chapter on the “ Sea ” is the best in the volume, and 
contains an account of an interesting experiment performed by the author to 
