824 



SCIENCE. 



[Vol. II., No. 47. 



of science is likely to look forwivi-d to text- 

 book making as u source of lionor as well as 

 of rcmiineiation ; as a task that may not onlj- 

 lielp others on their way, but aid himself to a 

 broader and more careful view of his own field 

 of labor. The text-books of Lyell, Jnkes, 

 and Dana in geology are among the admirable 

 works of these great authorities, and were 

 doubtless helpful to them iu their careers, as 

 they have been vastly advantageous to those 

 who have been trained bj- them. From a 

 purel}- litcrar3- point of view, text-book mak- 

 ing has no mean value to their makers. To 

 collect the stores of learning of a science, to 

 take that which has general value from the 

 mass of details, to secure a due proportion and 

 perspective to the parts of the work, — this is 

 a task indeed. 



Mr. Geikie has proven himself strong enough 

 for this burden. His store of facts is far larger 

 than has hitherto been gathered in any one 

 book on geologj'. Thej' show a large general 

 reading, not only in the vast geological litera- 

 ture of his own island, in the making of which 

 he has had a large share, but in the work done 

 in other lands, — a praise that can be given 

 to few of his countrj-men. In his list of 

 authorities he gives more names of scientific 

 men of other countries than of British geolo- 

 gists ; and this although he professedly desires 

 to take his illustrations as far as possible from 

 his own ground. 



Besides the peculiarly large amount of well- 

 gathered fact that marks this work, we ma}' 

 note among its ijeculiarities the considerablj' 

 wider range in the method of treatment of the 

 subject. In his first Iwok he gives twenty-four 

 pages to the cosmical relations of the earth, and 

 under this heading presents the fullest and most 

 satisfactory statement of the general condition 

 and history of the earth as a member of the 

 solar system that has yet been given in a popular 

 treatise. With the same freedom of treatment, 

 he does not hesitate to give a much fuller dis- 

 cussion of mineral veins than has hitherto found 

 its way into any text-book. So, too, with those 

 portions of the text that treat of river-action, 

 volcanic phenomena, and the other leading 

 manifestations of the geological forces. The 

 author evidentlj' feels a sense of freedom in 

 making his book that is to be commended even 

 if it gives him in the end near a thousand 

 pages of text. 



The paleontological part of the work is care- 

 fulh' done, but it is in the nature of the subject 

 that it should bo less commendable than the 

 other parts of the book. There is a radical 

 difficulty in treating paleontology, especially 



in Its department of liistorical geology, in any 

 text-book fashion. Even within the ample 

 limits given b}' a thousand pages of print it 

 comes down to a list of specific names that can 

 only convey a meaning to the masters of the 

 science ; while the first principle of a text- 

 book should be, that any statement should have 

 a free comprehensibility within itself, williout 

 recourse to libraries or collections. Page after 

 page of specific names hinders rather than helps 

 the beginner. 



This is the only criticism that can be made 

 on the historic geology of the book, and it is 

 one that lies against all the text-books that 

 have thus undertaken to treat a subject that is 

 so essentially unfit for this use. The essays on 

 the divisions of the rock series are admirable. 

 Especially to be commended is that on the old 

 dispute concerning Cambrian and Silurian. It 

 is pleasant to find a successor of Murchison in 

 the directorship of the British survey who can 

 do even-handed justice to the famous dead who 

 fought this great battle over the division of the 

 lower paleozoic section. 



At several other points in the series of rocks 

 we find an excellent spirit of discrimination ap- 

 plied to the problems of stratigraphic geology. 

 We note the following. In discussing the rela- 

 tions of Permian to carboniferous rocks, the 

 author notes the important fact, that, while in 

 Europe there are discordances and sharp con- 

 trasts between the Permian and the carbonifer- 

 ous series, there is no such trenchant line iu 

 Arrierica. In the same spirit the indistinctness 

 of the line between the triassic and the Jurassic 

 series in North America is carefulh" pointed 

 out. We find, also, that the doubt concerning 

 the position of the Flysch series of the Alps is 

 v^^ell presented ; the ground being taken that 

 the lower part of this series is upper cretaceous, 

 the higher portions, eocene. This is the best 

 brief presentation of this important problem 

 that is known to the present writer. The only 

 important exception that we can take to this 

 admirable presentation of the stratigraphic 

 problems concerns the author's general treat- 

 ment of the triassic period. He notes that the 

 European triassic series, with its reddish sand- ' 

 stones and shales, with connected gypseous 

 and rock-salt beds, is essentially local in char- 

 acter, and that this aspect of the series cannot 

 be expected in foreign lands. To this no 

 objection can be taken ; but he fails to assert 

 the equ.ally important fact, that reddish sand- 

 stones and shales have a singularly wide distri- 

 bution in other lands. This general character 

 of the trias constitutes it one of the most 

 puzzling portions of the geological section, and 



