Murchison’s Siluria. 395 
regions explored, illustrated by 50 quarto plates. ‘These volumes 
on Russia and the Urals are the joint production of Sir R. I. 
Murchison, Mr. Edouard de Verneuil of France and Count Alex- 
ander von Keyserling of Russia. 
The recent work of Sir R. I. Murchison is an able resumé of 
all that has been done by these writers, together with the results 
of other laborers in the science, among whom are Professor Sedg- 
wick of Cambridge, England, the geologists of the Ordnance Sur- 
vey in Great Britain, and many eminent men on the continent of 
Europe and in America. The observations on gold and its dis- 
tribution, with which the volume closes, are of much practical 
value, although only incidentally connected with the main object 
of the work. 
The important labors of the author of Siluria have been carried 
through with signal ability, and at a great outlay of time and 
money. Geology is largely indebted also to Prof. Sedgwick for 
his researches among the oldest fossiliferous rocks. But Murchi- 
son appears to have first made out the correct relations of these 
early strata. To him we owe the judicious exposition of the 
whole subject in the elaborate works which he has put forth, 
The candor and liberality manifested by the author are worthy 
of the works which they adorn. His investigations have ex- 
tended above the coal, into the New Red Sandstone, the Permian 
beds, and the Triassic, and the present work embraces these 
limits. 'The full exhibition of these great zones of primeval 
life, from its earliest dawn through many successive ages, to the 
eraof the first reptiles, is most interesting and instructive. A 
general review of the subject, partly historical and partly exposi-_ 
tory, is presented in the introductory chapter of the Siluria which 
we here cite. We take pleasure in thus showing our apprecia- 
tion of the extended labors of the author.—-s. s. | 
as to allow the superficial portion to become solid, has been adop- 
ted by the greater number of philosophers who have grappled 
