October 26, 1900.] 



SCIENCE. 



645 



chemistry does not appear to develop in the 

 student the power of conducting original 

 research, and at the same time to endeavor 

 to suggest some means by which a more 

 satisfactory state of things might be brought 

 about. I have not been able, within the 

 limits of this address, to consider the con- 

 ditions of study during the third year of the 

 student's career at college, or to discuss 

 the increasing necessity for extending that 

 course and insisting on the student carry- 

 ing out an adequate original investigation 

 before granting him a degree, but I hope on 

 some future occasion to have the opportu- 

 nity of returning to this very important part 

 of the subject. If any of the suggestions 

 I have made should prove to be of practical 

 value and should lead to the production of 

 more original research by our students, I 

 shall feel that a useful purpose has been 

 served by bringing this matter before this 

 Section. In concluding I wish to thank 

 Professor H. B. Dixon, Professor F. S. Kip- 

 ping, and others, for many valuable sugges- 

 tions, and my thanks are especially due to 

 Dr. Bevan Lean for much information 

 which he gave me in connection with that 

 part of this address which deals with the 

 teaching of chemistry in schools. 



W. H. Perkin. 



SCIENTIFIC BOOKS. 

 La face de la terre. By Edouard Subss. 

 Translated from the German Das Antlitz der 

 Erde, by Emmanuel De Margerie and 

 others. Vol. II. Paris, Armand Colin & 

 Cie., 1900. Pp. 878. 



The first volume of this important transla- 

 tion has already been noticed in the pages of 

 Science (Vol. VII., p. 803). The second vol- 

 ume contains the third part of the work dealing 

 with 'The Seas.' After a brief review of the 

 opinion of geographers concerning the question 

 of changes of level of the sea in relation to the 

 land, Suess adopts a terminology intended to 

 avoid any implication of the movement of the 

 land in relation to the sea In observed dis- 



placement of shore-lines. These ' shifts of 

 relative level,' as Robert Chambers termed 

 them, are then qualified as negative when the 

 sea-level appears to fall and positive when it 

 appears to rise, in accordance with the termi- 

 nology employed in reading tide-gauges. For 

 the expression ' elevation of the continent,' 

 we may substitute then ' negative displace- 

 ment of the shore-line,' and for 'submergence 

 of the continent,' positive displacement. 



The geological structure of the lands about 

 the Atlantic is treated with much care in order 

 to bring out the history of displacements of 

 shore-line in this part of the world. A similar 

 discussion is devoted to the contours of the 

 Pacific Ocean. In summarizing the characters 

 of these two great ocean basins, Suess finds 

 that "with the exception of the Cordillera of 

 the Antilles and of the mountainous trunk of 

 Gibraltar which circumscribes the two Mediter- 

 raneans, no part of the contours of the Atlantic 

 Ocean is determined by a folded chain. The 

 internal border with groups of folds, the coasts 

 cut by rias indicating a sinking of chains, the 

 inclined fractures of horsts and the step-faults — 

 such are the varied elements which determine 

 the plan of the shores of the Atlantic Ocean." 



As for the Pacific Ocean, "with the ex- 

 ception of a segment of the coast of Central 

 America in Guatemala where the Cordillera 

 making the turn of the Antilles is depressed, 

 all parts of the border of the Pacific Ocean, 

 of which the geology is known, are formed by 

 chains of mountains folded towards the ocean 

 in such a way that their external plications 

 serve to outline the continent itself or consti- 

 tute a belt of peninsulas and aligned islands." 

 He then considers the ancient Paleozoic seas 

 with the view of sifting the evidence which 

 their sediments and faunas present in relation 

 to the question of ' submergence and emer- 

 gence of lands ' and ' movements of the 

 hydrosphere.' Our author finds insuperable 

 difiiculties in the commonly accepted explana- 

 tion, and in this and following sections of the 

 work develops the idea of swayings of the 

 ocean waters alternately towards the equator 

 and the poles to account for the numerous 

 instances of advance and retreat of the sea 

 aflfbrded by the Paleozoic and Mesozoic for- 



