﻿328 Remeivs — Dana's Mineralogy. 



iron.^ The altered portions are sometimes separated by a sharp line 

 from, at other times graduate imperceptibly into, the unaltered. The 

 uufossiliferous ferruginous or pale-green part of such beds has not 

 seldom been separated from the unaltered part as a posterior forma- 

 tion, whilst the irregularity of the line of junction (due to varying 

 porosity or to the presence of protecting beds of clay), has iDeen 

 described as proof of unconformity between the two series. W.H.D. 



11. — A Text-Book of Mineralogy, with an Extended Treatise 

 ON Crystallography and Physical Mineralogy. By Edward 

 S. Dana. On the Plan and with the Co-operation of Prof James 

 D. Dana. With upwards of 800 Woodcuts and one Coloured 

 Plate. 8vo. pp. 485. (New York, John Wiley & Sons; 

 London, Triibner & Co., 1877). 



AMONG the various writers who have contributed systematic 

 works, text-books and guides, to the science of Mineralogy, 

 no author so richly deserves the thanks of English students of this 

 branch of study as Professor Jaraes D. Dana, of Yale College, New- 

 haven, Ct., U.S.A., the father of Mr. Edward S. Dana, the editor and 

 part author of the volume before us. When it is borne in mind that 

 the first edition of "A System of Mineralogy," by James D. Dana, 

 appeared as long ago as the yeai- 1837, and that the jiftli and last 

 edition appeared in 1868, it will, we think, be readily conceded that 

 we owe to Prof. Dana a vast obligation for his valuable services to 

 miueralogical science. Nor have these several editions been, as is too 

 often the case, merely reprints slightly modified and corrected ; but 

 in great part they have been re- written and largely increased in extent 

 of contents ; so much was this the case that in the 1868 edition it 

 was found necessary to greatly abbreviate the introductory chapters 

 on chemical and determinative mineralogy, the great feature of the 

 fifth edition being the descriptive portion, which still remains un- 

 equalled by any work on this subject in the English language. 

 The great demand for Dana's System of Mineralogy led its author to 

 undertake, in 1868, the preparation of a "Text-Book of Mineralogy "; 

 but the state of Prof. Dana's health however early compelled him to 

 relinquish the work, and he was not able subsequently to resume it. 



Finally, after the lapse of seven years, the editorship of the volume 

 was placed in the hands of Prof. Dana's son, Mr. Edward Salisbury 

 Dana, who has with great care endeavoured to carry out his father's 

 original plan. 



The work has been arranged with a view to meet the requirements 

 of class instruction. With this object in view the descriptive part 

 has been made subordinate to the more important subjects embraced 

 under Physical Mineralogy. Thus the Text-Book now issued forms 

 a companion volume to the fifth edition of the System of Mineralogy 

 published in 1868, rather than as superseding it. 



The Crystallography is presented after the methods of Naumann ; 



1 The Red Crag of Suffolk and the yellow flagstones of the Carboniferous Books 

 are, in certain cases of protection from oxidation of their contained iron, of a greyish- 

 blue colour. 



