570 Reviews — E. H. C. Craig — Oil-finding. 



entitled Miscellaneous there are remarks on the relation of ground- 

 water to disease, mainly by Mr. Baldwin Latham; notes on gases in. 

 wells and well-waters; and statements on. the Law of Underground 

 Water witli especial reference to the county. A bibliography and 

 excellent index complete this important and useful work. 



Til. — Oil-finding: An Introduction to the Geological Study of 

 Petroleum. By E. H. CuNiNrrNGHA.M Craig, B.A., F.G.S. ; with 

 an introduction by Sir Boterton Redwood, Bart. pp. xi + 195. 

 London : Edward Arnold, 1912. Price 8s. ^d. net. 



OWING to the greatly increased employment of petroleum of late 

 years, its production and mode of occurrence in the earth's crust 

 have naturally attracted considerable attention. Mr. Cunningham 

 Craig's book should, therefore, prove of interest to a wide cii'cle of 

 readers. The autlior very properly points out the erroneousness of 

 the supposition that the petroleum industry can be practically con- 

 sidered apart from scientific considerations, and that the finding of 

 petroleum in a given area ought not now to be a matter of mere 

 speculation. His treatment of the subject is bold, and he expresses 

 his opinions strongly and clearly ; and, although these may not be 

 generally accepted, they may at least have the good effect of stimulating 

 discussion. 



Unlike previous writers, Mr. Cunningham Craig regards the origin 

 of petroleum as the question of vital importance, and to which all 

 others must be subsidiary. The arrangement of the book is in 

 keeping with this standpoint; the discussions throughout are logical, 

 and the appeal to facts frequent ; but as regards these facts much 

 must depend on their selection. Of the various theories that have 

 been advanced to account for the origin of petroleum, the author is 

 a special pleader for that which ascribes it to terrestrial vegetation. 

 He admits that the frequent association of salt and brine with 

 petroleum is difficult of explanation in the face of his theory ; still, 

 with respect to this point he thinks that future research will produce 

 results of the greatest importance. His present opinion, however, is 

 that the association is accidental. Separate chapters are devoted to 

 processes of formation, migration, subterranean storage, and geological 

 structure, and the author emphasizes the importance of the study of 

 lateral variation, by which alone can oil-forming and oil-bearing 

 conditions be recognized. Useful hints as to field and indoor work 

 are given in the last two chapters. These, although intended for 

 beginners, might well be consulted by persons of more experience. 

 The book is illustrated by thirteen plates of photographs, chiefly of 

 scenes in Burma and Persia, and is furnished with a copious index. 



VIII. — The Sedimkntary Deposition of Oil. Bv Murray Stewart, 



D.Sc, r.G.s. 



TMHE author of this pamphlet, which is reprinted from the Records 

 1 of the Geological Survey of India, vol. xl, pt. iv, pp. 320-33, 

 IP 10, is one of the comparatively few British geologists who have 



