700 BOOK REVIEWS. 



BOOK REVIEWS. 



A Guide to the Determination of Eocks : Being an introduction to Lithol- 

 ogy. By Edouard Jannettaz, Docteur es- sciences. Translated from the 

 French by Geo. W. Plympton, C. E., A. M. D. A. Yan Nostrancl, Pab- 

 lisher, New York. For sale by Matt. Foster & Co. Price $1 50. 



This is a duodecimo volume of 165 pages, intended by the translator, who 

 is Professor of Phj^sical vScienrc in the Polytechnic Institute, Bi'ooklj^n, K". 

 Y., as a desirable supplement to the ordinary Academic course of geology 

 and an eas}" introduction to the larger treaties on Lithology. How far it 

 will accomplish these objects depends largely upon the advancement made 

 beforehand by the student in crj'stallography and microscopy, upon which to 

 some extent the determination of rocks as taught in this work depends. — 

 However, in most resjTects, it is plainly written, and well adapted to the 

 wants not only of the class for whom it was prepared, but also for practical 

 workers in the field. 



The introduction is a concise description of rocks, divided into Crystal- 

 line, Sedimentary and Eruptive, their origin, formation constitution and 

 modifications. 



Part I. is devoted to the ]!:-iiicipal physical and chemical properties of 

 the mineral species which cotupose the rocks, such as Feldspars and the 

 minerals allied to them : the Micas, the Chlorites or talcose Micas ; Talc and 

 Steatite; Amphiboles, aS Hornblende, etc.; Pyroxenes; Mineral species occa- 

 sionally appearing as essential elements of rocks, like Topaz, Tourmaline, 

 Garnet, etc. 



Part II. is devoted to a description of rocks and the minerals which com- 

 pose them, and consists of a more minute examination of the same classes 

 or species named above with their dominating and essential elements aud 

 their accessory and accidental elements. 



In Part III., the author fii-st presents the prominent characteristics of 

 rocks which enable the student to refer anj- specimen under consideration 

 at once to a certain group, and after that gives the method of determining 

 its precise order and name. 



Part TV is translated from the elementary course of applied geology by 

 M. Stanislaus Meunier, and gives the Dichotomic table for determining 

 rocks. 



As 'an illustration of the manner adopted by the author, we reprint part 

 of the chapter descriptive of Metallic Eocks in Part II. 



SULPHIDES AND SULPIIO-ARSENIDES. 



Heated on charcoal with carbonate of soda, they j'iold sodium sulphide 

 which blackens lead paper or silver foil. Heated in the oxidizing flame, 

 they yield sulphurous acids. 



