432 Reviews — Bauerman's 3Imerahgy. 



But fault-finding must end here, and we trust that what we have 

 said before will make it evident to all interested in the rocks or 

 fossils of the neighbouring continental shores that Dr. Mourlon has 

 produced a work of sterling value, and one which, in the absence 

 of Prof. Dewalque's long-expected second edition of his Prodome, 

 must become the vade-mecum to all scientific travellers in Belgium. 



G.A.L. 



II. — Text-Book of Systematic Mineralogy. By Hilary Bauer- 

 man, F.G.S. (London, Longmans, Green and Co., 1881.) 



THE above work on Mineralogy by Mr. Bauerman, which was 

 to have formed only one volume of the " Text-Books of 

 Science," has been divided into two parts, in consequence of the 

 systematic portion forming the present volume having been extended 

 somewhat more than was originally intended, so that the physio- 

 graphy or descriptive mineralogy will be issued as a companion 

 volume. 



The geometrical properties and symmetry of crystalline forms, 

 although treated in a general and sometimes original manner, occupy 

 about one-half of the work, each of the six systems, their combina- 

 tions and hemihedral forms being fully described, the derivati(m of 

 the latter as well as the tetartohedral modifications are illustrated by 

 shaded figures. The notations of Miller, Naumann, Weiss, Schrauf, 

 and Levy are described ; the faces of the crystals are marked 

 according to Miller, except in the hexagonal system, where the 

 Bravais-Miller method is used, but in the descriptive text the symbols 

 of Weiss are sometimes noted, but those of Naumann are mostly 

 given throughout. 



Comparative tables of the different notations as well as the names 

 proposed for the six systems by their authors would have been 

 useful. The physical characters of minerals are concisely given and 

 their optical and thermal properties are described at great length, 

 considerable attention being directed to the subject of polarisation, 

 and a table is appended showing the optical constants of the 

 principal transparent minerals. The remaining portion of the work 

 is devoted to the chemical properties of minerals, the relation of form 

 to chemical composition, and the association and distribution of 

 minerals. The latter may be usefully consulted as bearing on this 

 interesting part of mineralogical science, as it treats in a clear and 

 concise manner of the origin, alteration, pseudomorphism, and para- 

 genesis of mineral substances. 



A few minor points may require revision, but the work will be 

 found a useful guide to students desirous of acquiring a general 

 knowledge of the subject, as well as serve as an elementary 

 introduction to larger text-books, — the main objects the author had 

 in view in preparing the present volume. 



