Bihlioffraphical 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: — 1st. Dynamical geolog}, 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. Tliis 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 1 7 treats of the three later 

 Palaeozoic 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 m 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 Clymeniee of 

 the Rhenish rocks should have had their woodcuts like other cha- 

 racteristic fossils. Although the author's cluipter 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." AVe think, however, that a notice of the special fossib 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 collie-teachers 

 must now feel that it possesses. 



In spite of this, nowever, 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, 



