Reviews —Lyells Elements. 167 
jaspers into earthy minerals of very different appearance, and silicify 
wood and other organic bodies. In the same way, water has cer- 
tainly produced very considerable and special deposits in mineral 
veins, being indeed the chief agent in their metamorphism. ‘There 
can be no doubt that water has had much to do in all phenomena 
connected with the deposit of minerals in crevices and veins. 
Distinct relations may often be traced between mineral springs 
and volcanic disturbances; and M. Lecoq sees in this something to 
confirm him in his view, often expressed, that lavas proceed from 
below all metamorphic rocks, including granites. In finally treating 
of the origin of mineral springs, he recapitulates some of the prin- 
cipal points alluded to in the early chapters of his book, and quotes 
M. Pissis and his observations on the Andes as confirming the views 
he has expressed concerning the Auvergne district. He concludes 
with a brief résumé of his arguments. We must leave our readers 
to examine these for themselves, if they are inclined to do so. ‘The 
book is interesting, though much of the matter has already appeared; 
and the theory, if not original, is pertinaciously advocated. ‘There 
is no doubt, however, that a careful and exact study and record of 
the main facts concerning important groups of mineral springs 
would be very valuable, both immediately and as a standard of 
comparison hereafter. Such a record is commenced in France, and 
should be made in other countries also.—D. T. A. 
REVIEWS. 
—+~—_- 
ELEMENTS OF GEOLOGY; OR, THE ANCIENT CHANGES OF THE EARTH 
AND 1Ts INHABITANTS, AS ILLUSTRATED BY GEOLOGICAL MOoNU- 
mMEeNts. By Sir Cuarves Lyett, Bart., F.R.S., &c. Sixth Edition, 
ereatly enlarged, and illustrated with 770 Woodcuts. 8vo. pp. 794 
London: Murray. 1865. — 
HE first edition of this work was an expanded form of one of 
the chapters of the author’s ‘ Principles,’ and was termed the 
‘Elements of Geology; it subsequently, in several editions, was 
enlarged more and more as the ‘ Manual ;’ and now, having absorbed 
the several Supplements published since its Fifth Edition in 1855, it 
again comes before us as the ‘ Elements,’ carefully elaborated by its 
distinguished, experienced, and enthusiastic author, especially in his 
own lines of research. We do not see much alteration in the first 
nine chapters; but the ‘Tabular View of the Fossiliferous Strata,’ 
pp-102—106, has been re-planned, with some improvements. Chapters 
x.—xili., which follow, treating of ‘Recent and Post-Pliocene Periods,’ 
and including Fossil Man and the Antiquity of the Human Race, Lake- 
dwellings, History of Caves, Glacial Conditions, and all the interest- 
ing facts and questions thereto belonging, are re-written, and full of 
valuable material, which the author has collected with care and judg- 
mént, and conscientiously verified by personal research. In his 
well-known ‘ Geological Evidences of the Antiquity of Man’ (in three 
