TRANSLATIONS AND NOTICES 



OF 



GEOLOGICAL MEMOIRS. 



Classification and Description of Rocks. By Dr. Ferdi- 

 nand Senft, &c. 8vo. Breslau, 1857, pp. 442 ; with 12 Tables. 



[Classification und Beschreibung der Felsarten, $*c] 



To the above work by Dr. Senft, of Eiseuach, was accorded in 

 1855 the Demidoff prize, offered by the Leopold and Caroline Aca- 

 demy of Breslau, for the best essay on the Classification and De- 

 scription of Rocks. 



The work is divided into two principal parts : the first (pages 3 

 to 82) contains the general introductory matter necessary to a 

 knowledge of rocks, followed by descriptions of the distinction and 

 determination of the classes, orders, genera, species, and individual 

 varieties of rocks, which are arranged in a series of tables, with 

 a brief diagnosis of each individual rock. The second and far 

 larger portion of the work (pages 83 to 422) embraces the detailed 

 characterization and the chemical analyses, with full indications of 

 the position and mode of occurrence of every variety of rock-mass 

 known to the author. 



The copious information, both special and general, contained in this 

 second part is very important, interesting, and highly useful, and 

 indicates the vast amount of care and labour which the author has 

 bestowed in rendering this work not only serviceable to the student, 

 but a necessary work of reference to the geologist. To this end 

 the author subjected a very large series of specimens to mechanical 

 and chemical analysis. That omissions may occur and corrections 

 be necessary, there is no doubt ; but the mass of information em- 

 bodied in the volume is far larger than is to be found in any present 

 treatise on rocks and rock-structure, — subjects to which but little 

 attention has been paid in this country since the publication of the 



VOL. XIV. PART II. B 



