Bibliographical Notices. 69 
books that characterize them as the works of different thinkers ; and 
there are peculiarities that may interfere with the fulfilment of their 
intended usefulness. 
Mr. Jukes’s ‘School-Manual’ takes a three-part view of the 
science, namely :—Ist. Dynamical geology, or geological operations 
now in action, prefaced with a chapter descriptive of the earth as a 
whole, and comprising, in the chapter on igneous rocks, a brief ac- 
count of the chief rock-substances ; 2. Descriptive geology, or some 
of the facts observable in the crust of the earth; 3. Theoretical or 
historical geology—the history of the formation of the earth’s crust, 
deduced from the facts observable.in it, as interpreted by the opera- 
tions now going on. This is a philosophical treatment of the sub- 
ject, and is very well carried out to the extent intended by the au- 
thor, except in one particular. Chapter 17 treats of the three later 
Paleozoic periods—the Devonian, Carboniferous, and Permian pe- 
riods; but whilst the last two are described and illustrated, the first 
is replaced by seven pages of technical argument as to whether the 
**Devonian” strata should have a place in the geological scale or 
not, geologists not having yet fully examined these beds in Devon, 
Cornwall, Wales, Scotland, Ireland, and elsewhere. Still the strata 
and their peculiar fossils do exist; and whether the divisional lines 
between them and the Silurian, and between them and the Carboni- 
ferous strata, are more or less distinct is of minor importance in a 
little book like this, where the well-known “Old Red”’ Fishes of 
Scotland and the wide-winged Spirifers and peculiar Clymenie of 
the Rhenish rocks should have had their woodcuts like other cha- 
racteristic fossils. Although the author’s chapter on the ‘ Devonian 
Period” (which he does not admit) reminds one of the famous Hiber- 
nian chapter ‘On Snakes,” and a chapter ‘On Oolite”’ in a work 
on the Plymouth Limestones,—the non-existence of oolite being the 
briefly stated fact, yet the pressing interest of an earnest and honest 
writer’s own views and special work must be taken as an excuse for 
his rather pointing out difficulties in theoretical geology, in this in- 
stance, than following the usual routine of “Old Red”’ and ‘ Devo- 
nian.” We think, however, that a notice of the special fossils and 
sections, with a warning allusion to the doubts entertained as to the 
exact relationships of the beds, and of their value in geologic time, 
would have fulfilled the requirements of the case, and thus left the 
book free of the blemish which all schoolmasters and college-teachers 
must now feel that it possesses. 
In spite of this, however, the ‘School-Manual’ is admirably 
adapted to attain the chief object for which it was written—namely, 
to impart sufficient rudimentary knowledge to excite and guide the 
faculty of observation with regard to rain and snow, glaciers and 
rivers, sea-shores and ocean-beds, hot springs and volcanos, lavas 
and strata, minerals and fossils, so that the young student may get 
hold of the groundwork of geology, and the grown-up amateur may 
gain from it a fair general notion of the scope and nature of the science. 
Professor Phillips’s ‘Guide to Geology’ first appeared nearly 
thirty years ago, when elementary treatises by Brande, Bakewell, 
