1872.} Notices of Books. 369 
its various strata are described and localised, the fossils it 
contains catalogued and delineated, and the theories derivable 
therefrom remarked and discussed. In one chapter the changes 
of the earth’s surface from upward and downward movement, 
from the wearing away of rivers, and from the deposit of floods, 
is exemplified from this one typical river-basin. Finally, a single 
chapter discusses the economical questions of the amount and 
quality of the supply of coal, iron, brick and pottery earth, ochre, 
Fuller’s earth, glass, sand, and last, not least, water. 
In this way does the Oxford Professor both inculcate the 
theory ard show by practice that observation is necessary to the 
foundation of this science; that geology is a philosophical study 
branching off into many kindred sciences, and that it has a 
practical value for chemist, agriculturist, miner, metallurgist, 
and engineer; and like every other branch of natural science, it 
leads from phenomena which our senses can observe to dis- 
coveries useful to man in every career. é 
Volcanos, the Character of their Phenomena, their share in the 
Structure and Composition of the Surface of the Globe, and 
their Relation to its Internal Forces. With a Descriptive 
Catalogue of all known Volcanos and Volcanic Formations. 
By G. Poutett Scropr, F.R.S., &c. Second Edition, with 
Prefatory Remarks, and a List of recent Earthquakes and 
Eruptions, &c. London: Longmans. 1872. 
WE notice the second edition of this exhaustive work on 
Volcanos, both because it is a long time, thirty-seven years, since 
the first edition was published, and also because some con- 
siderable additions have been made in the present issue. The 
list of recent eruptions extends from 1860 to the end of August, 
1871, and includes those disturbances which are not mentioned in 
the body of the work nor in the catalogue of existing volcanos. This 
makes the information rather scattered, and any one who wishes 
to become possessed of the whole history of a particular 
mountain, after he has read the account in the first Appendix, 
has to search through the list in the second for the records of 
subsequent eruptions. The other new objects discussed are the 
igneous fluidity of the interior of the globe, the true character 
of lavas, the coincidence of volcanic and atmospheric dis- 
turbance and tidal action, the foliation of the (so-called) 
metamorphic crystalline rocks, and the ratio of development of 
subterranean forces. In the first case our author decides against 
internal fluidity, and in favour of the origin of disturbance at 
comparatively small depths. He is inclined to think that lavas 
in their most molten condition are not homogeneous masses, 
but include most of the crystals to be afterwards found in them 
in a state of mechanical mixture in their more fluid materials, 
VOL.. El.. (N-S:) 3B 
