478 
THE GEOLOGIST. 
tlien existed in the condition of a transparent and permanent gas, min<^led 
with the atmosphere surrounding the earth, and protecting it like a dome 
of glass. To this effect of carbonic acid it is possible that other gases may 
have contributed. The ozone, which is mingled with the ox3'gen set free 
from growing plants, and the marsh gas, which is now evolved from de- 
composing vegetation under conditions similar to those then presented by 
the coal-fields, may, by their great absorptive power, have very well aided 
to maintain at the earth's surface that high temperature the cause of which, 
has been one of the enigmas of geology." 
EEVIEWS. 
The Geology of the Country round LiveryooL By Geo. H. Morton, F.G.S. 
Towards the close of 1861 a lecture was delivered to the Liverpool Na- 
turalists' Field Club by the author, " On the Geology of the Country round 
Liverpool," which the Council of that Institution at once decided to pub- 
lish. Since that period the author has re-surveyed and confirmed his 
original investigations, and otherwise matured and improved his work for 
presentation to the public. Ten years ago the subdivisions and super- 
position of the Triassic rocks in this district had not been determined, al- 
though Mr. Cunningham had as early as 1838 made known the occurrence 
of fossil footprints in the strata of the Storeton quarries ; and it was not 
\intil Mr. Hull, who had then just completed his examination of the dis- 
trict for the Government Geological Survey, read a paper on the results 
of his labours before the British Association in 1854, that the details of 
these important beds were published. The book before us gives a concise 
and admirably clear account of the Liverpool district, commencing with 
the physical features of the country and the geological systems and forma- 
tions exhibited to obtain it. These consist of the coal-measures, and Trias, 
and Pleistocene deposits, including boulder-clay, and submarine forests. 
The faults, denudations of the beds, and general geological history of 
the district, are also treated with accuracy and perspicuity of description. 
The numerous plates and woodcuts give well-selected examples of fossils 
and geological and physical phenomena. These include a view of the sub- 
marine forest of Leasowe at Dove Point, sections from the river Dee to 
Hayton, of the strata round Liverpool, through the coal-measures at 
Prescot, of the Lower Soft Hed and Variegated Sandstone at Toxeth Park ; 
of the pebble-beds at Eastham, through Fairbrick and Bidston Hills, 
showing the junction of the Upper Soft Eed and Variegated Sandstone 
with the overlying Keuper Sandstone, of the Keuper at Liverpool and 
AVirral, of the strata along the three railway tunnels under the town, 
through the Lower Keuper at Storeton, across Wallasey Pool showing 
the submarine forest bed, along the Cheshire coast, from the lighthouse, 
Dove Point, Leasowe ; and plates of the footprints of the Cheirotherium, 
JRhyncJiosaurus, and other fossils. The accounts of the post-glacial de- 
posits are exceedingly interesting. The elevated ridges of sandstone tra- 
versing the district from north to south are generally free from drift, while 
the depth of the intervening valleys had been diminished by thick accu- 
mulation. The river Mersey occupies what was once the deepest of these 
valleys. From his examination of the shores, Mr. Morton considers the 
