160 Bibliographical Notices. 



the field. The mode of inculcation of such facts varies too miich 

 with books anil teachers. The mere exercise of memory in leaniiug a 

 table of elassiticalion is a jjoor sal)Stitnte for the knowledge obtaiued 

 by the student from a good practical teacher. 



After a succinct notice of the history of the science, in which the 

 origin of inductive geology forms an interesting aiid instructive sec- 

 tion, the author enters upou elciuentary \-icws of the structure and 

 composition of the crust of the earth and of the j)re8ervation and dis- 

 tribution of organic remains. 



To this succeeds a series of chapters descriptive of the primary, 

 hypozoic, palaeozoic, mesozoic, and cainozoic strata, in the ascending 

 order. In this respect we regard this plan of arrangement as pre- 

 ferable, inasmuch as it pro\'ides the student with the true suc- 

 cessional ordinatiou of the various geognostical phsenomeua. Thus 

 he is better enabled to trace the origin of the successive and deri- 

 vative strata, — the varying hydrographical areas more or less defined 

 by these deposits, — and the gradual advance, in different directions 

 and under varying circumstances, of vegetable and animal organisms ; 

 — and hence he is jiresented with a comprehensive view of the various 

 phases of the earth's physical history. 



Following the chaj)ters on descriptive geology is a chapter devoted' 

 to modern causes in action, — a section which we are inclined to think' 

 should take its place at the connnencernent of the work ; for the 

 ordinary mind, when acquainted with existing ]>hysical agencies, not 

 only better appreciates the present operations of nature, but possesses 

 an index and a key to the multitude and apparent mystery of ancient > 

 physical ph?enomena. 



Inorganic phsenomena, more especially those connected with the 

 effects of heat, are fully treated of in the next following divisions of 

 the work ; — oue chapter being devoted specially to the subject of 

 Mineral veins. 



In a subsequent chapter, on the state of geological theory, we 

 would particularly recommend to notice the section on geological 

 chronolog}', in which the probable rate of accumulation of deposits 

 is inferred from ihe study of the mechanical and chemical origin of 

 strata, — the alternations of beds of different lithological characters, 

 and of different natures, such as marine, freshwater, and igneous, — the 

 succession of races of imbedded organic I>eings, — and lastly, the repe- 

 titions of convulsious, and the metamorpliism of rock-masses. la 

 the same chapter we find two useful tables illustrative of the distinct 

 groups of animal life which have followed one another in a settled 

 order of geological time. The one, adapted from M. A. d'Orbigny, 

 affords a rough estimate of the proportional number of sjjecies of all 

 animals in the several geological groups ; the second, repeated from 

 the author's work on Yorkshire, has reference to the distribution in 

 time of the more prominent vertebrate types specially characteristic 

 of the great geological periods. 



The appendix of tables and calculations contains also some prac- 

 tical observations on the instruments used by the working geologist, 

 namely, barometers, clinometers, &c., with directions for the benefit 



