REVIEWS IQI 
Geology of Petroleum. By Witt1am Harvey Emmons. First 
Edition. McGraw-Hill Book Company, 1921. 
It is gratifying to record in this book by Professor Emmons a most 
notable contribution to geological education and one that was impera- 
tively needed, because of the unusual present interest in geology as 
applied to the occurrence of petroleum and natural gas. 
While the reviewer is not entitled by experience to pass judgment on 
the book from the viewpoint of the advanced specialist in petroleum 
geology, surely from the standpoint of the general geologist interested in 
petroleum occurrence the volume supplies a most welcome means of 
acquiring familiarity with special geologic problems connected with oil 
occurrence, and, as stated in the preface, the book was designed to meet 
this need on the part of professional geologists, and especially of college 
students already familiar with the fundamental principles of geologic 
science. ! 
The work is based on a series of lectures which for several years have 
been offered in courses in economic geology at the University of Minne- 
sota. Especially noteworthy is the large number of references indicat- 
ing that the author has made an exhaustive search of the literature. 
This feature makes the volume valuable as a source book, in addition 
toits primary purpose. Two hundred and fifty-four text figures, mostly 
line drawings, are judiciously selected. 
Chapter I, the introduction, includes sections on geographic and 
geologic distribution. Tabulations of geologic distribution bring 
out the notable fact that only in the United States have important 
oil reserves been found in rocks of Paleozoic age. Chapter II deals with 
surface indications of petroleum and methods for testing rocks for the 
presence of oil. 7 
Other chapters deal with the openings in rocks, the association of 
petroleum and salt water, reservoir rocks and covering strata, and the 
properties of petroleum and natural gas. Current views concerning 
the first stages of the formation of petroleum are covered in other chap- 
ters, as well as theories governing the accumulation of oil in pools. A 
very useful table is given showing the salient features of a large number 
of oil fields, including the age of the rocks, their kind, the nature of the 
cover, the structural character of the reservoirs, and the nature of the 
surface indications of petroleum. 
A long chapter is devoted to the structural features of oil and gas 
pools, and chapters of lesser importance are devoted to the effects of 
