328 
Bevietvs — Bana’s Mineralogy . 
iron. 1 The alteret! portions are sometimes separated by a sharp line 
from, at other times graduate imperceptibly into, tbe unaltered. The 
uufossiliferous ferruginous or pale-green part of such beds bas not 
seldom been separated from the unaltered part as a posterior forma- 
tion, wliilst tbe irregularity of the line of junction (due to varying 
porosity or to tbe presence of protecting beds of clay), bas been 
described as proof of unconformity between tbe two series. W.H.D. 
II. — A Text-Book of Mineralogy, with an Extended Treatise 
on Crystallography and Physical Mineralogy. By Edward 
S. Dana. On the Plan and with tbe 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, Trübner & Co., 1877). 
A MONG tbe various writers who bave contributed systematic 
works, text-books and guides, to tbe Science of Mineralogy, 
no author so ricbly deserves tbe tbanks of English students of tbis 
brauch of study as Professor James D. Dana, of Yale College, New- 
haveu, Ct., U.S.A., tbe father of Mr. Edward S. Dana, tbe editor and 
part author of tbe volutne before us. Wben it is borne in mind tbat 
tbe first edition of “ A System of Mineralogy,” by James D. Dana, 
appeared as long ago as tbe year 1837, and tbat tbe fiftli and last 
edition appeared in 1868, it will, we think, be readily couceded tbat 
we owe to Prof. Dana a vast Obligation for his valuable Services to 
mineralogical Science. Nor bave these several editions been, as is too 
often tbe case, merely reprints sligbtly modified and corrected ; but 
in great part they bave been re-written and largely increased in extent 
of contents ; so mach was tbis tbe case tbat in tbe 1868 edition it 
was found necessary to greatly abbreviate tbe introductory cbapters 
on Chemical and determinative mineralogy, tbe great feature of tbe 
fiftli edition being tbe descriptive portion, whicli still remains un- 
equalled by any work on this subject in tbe English language. 
The great demand for Dana’s System of Mineralogy led its author to 
undertake, in 1868, tbe preparation of a “Text-Book of Mineralogy 
but tbe state of Prof. Dana’s health however early compelled bim to 
relinquish the work. and he was not able subsequently to resume it. 
Finally, after tbe lapse of seven years, tbe editorship of the volume 
was placed in tbe hands of Prof. Dana’s son, Mr. Edward Salisbury 
Dana, who bas with great care endeavoured to carry out bis father’s 
original plan. 
Tbe work bas been arranged witli a view to meet tbe requirements 
of dass instruction. With tbis object in view the descriptive part 
bas been made subordinate to tbe more important subjects embraced 
under Physical Mineralogy. Thus the Text-Book now issued forms 
a companion volume to tbe fiftli edition of tbe System of Mineralogy 
publisbed in 1868, rather than as superseding it. 
Tbe Crystallography is presented after tbe methods of Naumann ; 
1 The Red Crag of Suffolk and the yellow flagstones of the Carboniferous Rocks 
are, in certain cases of protection from oxidation of their contained iron, of a greyish- 
blue colour. 
