1875.] Notices of Books. 265 
ciency he has therefore endeavoured to supply, and has produced 
a work which we feel convinced will be widely appreciated. The 
purpose of this treatise being purely practical, those interesting 
theoretical questions in which Geology is so rich are here passed 
over. For a history of the life of the primeval world, for the 
causes of the striking phenomena it presents, for paleontological 
research, the reader must look elsewhere. Dr. Page, we must 
add, has, in his former publications, proved his ability to deal 
with such subjects. After an Introduction, showing the im- 
portance of Economic or applied Geology to the farmer, the land 
agent, the builder, the engineer, the miner, as well as to most 
manufacturers, the Author gives a brief account of the “ rocky 
crust” of the earth, of stratified and unstratified rocks, their 
relative positions, texture, chemical composition, and chrono- 
logical arrangement. He then shows, in succession, the bearing 
of geology upon agriculture, upon the valuation of land, upon 
architecture, engineering (including road and railway making, 
the construction of canals and docks, and the supply of water), 
upon mining, the production of heat and light, the fictile arts. 
He then treats of grinding, whetting, and polishing materials, 
of fire-resisting substances, of pigments, dyes, and detergents, 
of salts and saline earths, of mineral and thermal springs, of 
mineral medicines, of gems and precious stones, of metals and 
metallic ores. A summary at the end shows the valuable 
products likely to be found in each geological formation. 
We need scarcely say that to deal exhaustively with all the 
subjects here enumerated would require not a volume, but an 
encyclopedia, and that of the bulkiest. Still whatever could be 
done within the compass of some three hundred closely-printed 
pages has been done. It would be difficult, indeed, to compress 
a larger amount of sound useful matter within the same limits. 
We may, however, venture to point out that in the chapter on 
dyes tin is omitted amongst the bodies mentioned as mordants. 
Nor do we think it strictly accurate to pronounce the coal-tar 
colours of inorganic origin. 
The work is illustrated with engravings, and accompanied 
with a geological map of the British Islands, placed, for better 
preservation, in a pocket within the cover. 
We cannot more fitly conclude this brief notice than by 
quoting the following excellent advice :—‘‘ Every surface efflores- 
cence, however insignificant, every trickle of styptic water (and 
every issue of water should be tested by the field geologist), 
every mealy disintegration of a rock, and even the presence of 
such plants as affect saline soils, should all be duly noted as 
indications of the mineral treasures below.” 
