Review of Recent Geological Literature. 319 
in the same direction. At Mont Pelee the position of the orifice 
of escape of these gases had a preponderating influence on their 
direction. 
"These clouds, possessing at their starting a high temperature 
which becomes slowly lessened, have a considerable mechanical and 
calorific force, which explains the complete annihilation of a large 
city and its inhabitants, as well as the extension of the destructive 
effects to the distance of ten kilometers from their point of origin." 
The scientific world is under obligation no more to the French 
republic than to the French savant for this grand and most satis- 
fcatory treatise. n h. \v. 
Minerals in rock sections; the practical methods of determining min- 
erals in rock sections with the microscope, especially arranged 
for students in technical and scientific schools. Lea McIlvaine 
Luquer, Adjunct professor of mineralogy, Columbia University, 
New York City, Revised edition. New York, D. Van Nostrand 
Company, 1905. 147 pages, $1.50 net. 
This revision of a useful and well-known text book has been 
improved by an enlargement of that part relating to the determina- 
tion of the plagioclases, by the explanation and illustration of the 
Becke method of relative refraction in contiguous minerals, and by 
many additions in chapters I, III and IV; also by tables of refrac- 
tive indices, of double refraction, and a diagram showing the rela- 
tion between strength of double refraction, interference colors and 
thickness of section, the last being an adaptation from Michel Levy's 
color scheme of double refraction accompanying Miner aux des 
Roches by Levy and Lacroix. N. H. W. 
Geology of Western Ore Deposits. Arthur- Lakes, late professor 
of geology at the Colorado School of Mines; New Edition, en- 
tirely rewritten and enlarged, with 300 illustrations, 438 pages. 
Kendrick Book and Stationery Company, Denver, Colo.. $2.50, 
postpaid. 
Colorado has the chief share in this work, although its descrip- 
tions range from Alaska southward. It is well illustrated, frequent- 
ly by sketches by the author, and its statements are correct and 
clear. The extended acquaintance of the author with the mining 
and methods of the Rocky mountain region has contributed a large 
share to the contents of this book though it is still largely, and nec- 
essarily, a compilation from other authorities — Emmons, Spurr, 
Weed, Van Hise, Kemp and others. The book cannot fail to be 
of great usefulness to the mining industry of the west. N. H. \v. 
( 
Grundziige der Gesteinskunde; 1 TeiU Allgemeine Gesteinskvnde als 
Grundslage dc Geologic Ernst Weinschenk, niit 47 Textfiguren 
und 3 Tafln. Seiten 163, 1902, 4 marks. Freiburg, Woin. Strass- 
