Bibliographical Notices. 167 



dition and properties of the substances met with near the eartli's 

 surface, — the forces of attraction and repulsion, light, heat, electri- 

 city, and chemical affinity, — the general distribution and changes in 

 the condition of matter at the surface, — the various effects produced 

 by atmospheric, aqueous, and organic agencies, — the reaction of the 

 interior upon the external surface, as in volcanic and earthquake phse- 

 nomena. The chapters on jNIineralogy contain the form, structure, 

 physical characteristics of minerals, and their classification ; the ar- 

 rangement, which has been modified, is upon the basic plan ; and the 

 list includes with synonyms 1400 names: the more important ininerals, 

 and those most useful in geological investigation, are more fully de- 

 scribed in the text. In alluding to the use of the blowpipe, it would 

 have been more useful if the author had given a concise account of 

 the discrimination and reaction of the chief metallic substances. The 

 Descriptive part comprises an account of the nature, mode of original 

 aggregation, and subsequent changes of the different kinds of rock, 

 their structure and mechanical displacement, and the classification of 

 them by means of fossils. In citing the laws of distribution of fos- 

 sils. Prof. Ansted has omitted the reference to Pictet, which was 

 properly referred to in the first edition ; for as some of the points are 

 open to controversy, it is but right that the authority for them should 

 be given. At p. 30/ is a table of the numerical proportion of genera 

 in the various rocks of the British Isles, compiled from the last edition 

 of Morris's 'Catalogue of British Fossils.' The paucity of the fauna 

 mentioned under Older Silurian may be accounted for by stating 

 that under this term are included merely the Lingula flags and beds 

 called 'Cambrian' by some authors, — the equivalents of the primor- 

 dial zone of Barrande in Bohemia, and of the alum-slates of Sweden. 

 The generic distribution of fossil plants is omitted from this table, 

 and is here given as reduced from the same work : — 



Sil. Dev. Carb. Perm. Trias. Ool. Cret. O.Tert, N.Tert. 

 4 3 61 7 4 53 8 20 8 



The chapters on the classification and distribution of the palaeozoic, 

 secondary and tertiary rocks and their fossils, follow; the descrip- 

 tion of these proceeds in a regular order from the older to the modern 

 groups, an arrangement which has many advantages over that which 

 recedes in the reverse or downward order, as adopted in the former 

 edition. We are glad, therefore, that Prof. Ansted has thought it 

 advisable to alter his former plan ; for surely it is better for the stu- 

 dent to trace upwards the successive phases in the history of the 

 globe, each of which has been partly dependent on the preceding, 

 than to commence with the existing order and travel backwards. 

 The growth by which the civilization of our own period has been 

 produced, would be less understood by a written history commencing 

 vnth the present dynasty. 



The fourth and concluding part is devoted to Practical Geology, 

 the matter being very much increased, improved, and more com- 

 plete than in the forme r edition. The subjects treated of are : — 

 agricultural geology, drainage, water supply, earthy minerals used 



