Reviews — Science Primers. 81 



they are near Co. Donegal, in Galway and Dingle Bays ; south and 

 east of Ireland, however, large surfaces with irregular outlines are 

 formed of mud. Mud-bottoms also are found in plenty around 

 Scotland. In these cases, submarine decomposition of unknown 

 outcrojDS is pointed to as their origin. 



The points of the sea-bottom which are bare, or rather where the 

 soundings could discover nothing but rock, are marked by the black 

 areas on the maps, and a study of these with reference to deep-water 

 currents would doubtless throw much light on their origin. The 

 nature of the rock itself is in these cases naturally often doubtful. 



The discussion of the last portion of M. Delesse's book, con- 

 sisting chiefly of an attempt, generally successful, to reconstruct the 

 physical geography of France at various epochs in its geological 

 history, must be for the present deferred. 



II. — SciKNCE Primers. Edited by Professors Huxley, Eoscoe, and 

 Balfour Stewart. Part V. Geology. By Prof. Geikie, LL.D., 

 F.R.S. 12mo., pp. 130. (London : Macmillan & Co., 1874.) 



THIS little primer is one of a numerous series, and is an ex- 

 cellent introduction for very young children to the vast subject 

 of Geological Science. 



The object of this series is to give its juvenile readers an insight 

 into the main facts of the different branches of science, in as simple 

 a way as possible, illustrating them with common and familiar 

 examples of every-day occurrence. 



This plan is well carried out by Prof. Geikie in the Part before us. 



The author first treats of the three different kind of rocks — 

 sedimentary, organic, and igneous — how and by what agencies each 

 was formed, and why fossils occur in the first two. He next takes 

 the crust of the earth, shows that it has been raised, depressed, and 

 contorted; how mountains have been formed, and "how the rocks 

 of the crust tell the history of the earth." 



Having thus brought his young readers to the threshold of 

 Geological Science, Prof. Geikie bids them adieu, leaving them, if so 

 disposed, to enter and discover the endless store within. 



The style is throughout easy, and the language simple. Every 

 fact is so clearly expressed and lucidly explained as to be entirely 

 within the comprehension of any child of ordinary capacity. There 

 are, besides, numerous well-executed woodcuts, in illustration of all 

 the principal points in the work. 



If we may judge of the series from the Part before us, we should 

 say that it is well qualified to supply the want, beginning to be felt, 

 now that Natural Science is becoming day by day more popular, and 

 more widely taught, of some good though juvenile works on its 

 different branches. Should the School Board ever introduce the 

 teaching of Natural Science into their system of education, we 

 would most heartily recommend these little books to their con- 

 sideration. 



We should not omit to add that collections containing twenty-two 



DECADE II. — VOL. I. — NO. II. 6 



