506 Notices of Memoirs — 0. C. D. Boss — On Petroleum. 



IX. — The Origin of Petroleum. By 0. 0. D. Eoss. 



IN the course of introductory remarks the author contenrls that, 

 owing to the mystery surrounding the origin of petroleum, 

 and to the paucity of indications where to seek for it, practical men 

 in this country distrust the permanence of the supply, and hesitate 

 to adopt it for many useful purposes ; while the object of this paper 

 is to suggest a way of resolving the mystery which is calculated to 

 dissipate that distrust. The theories suggested by Reichenbach, 

 Berthelot, Mendelejeff, Yirlet, Verneuil, Peckham, and others, which 

 are briefly described, make no attempt to account for the exceeding 

 variety in its chemical composition, in its specific gravity, its boiling- 

 points, etc., and are all founded on some hj'pothetical process which 

 differs from any with which we are acquainted ; but modern geo- 

 logists are agreed that (as a rule) the records of the earth's history 

 should be read in accordance with those laws of ligature which con- 

 tinue in force at the present day. E.g., the decomposition of fish 

 would not now produce paraffin oil ; hence we can hardly believe it 

 possible thousands, or millions, of years ago, so long as it can be 

 shown that any of the ordinary processes of Nature are calculated 

 to produce it. The chief characteristics of petroleum strata are 

 enumerated as : I. The existence of adjoining beds of limestone, 

 gypsum, etc.; II. Volcanic action in close proximity; III. The 

 presence of salt water in the wells; IV. The great extent of the 

 production of oil, indicating subterranean receptacles of vast 

 dimensions. 



I. The close and invariable proximity of limestone to the wells 

 has been noticed by all writers, but they have been most impressed 

 by its being ' fossiliferous,' or shell limestone, and have drawn the 

 erroneous inference that the animal matter once contained in those 

 shells originated petroleum, but no fish oil ever contained paraffin. 

 On the other hand, the fossil shells are carbonate of lime, and, as 

 such, capable of producing petroleum under circumstances such as 

 many limestone beds have been subjected to. All limestone rocks 

 were formed under water, and are mainly composed of calcareous 

 shells, corals, encrinites, and foraminifera, the latter similar to the 

 foraminifera of ' Atlantic ooze ' and of English chalk beds. Every- 

 where, under the microscope, its organic origin is conspicuous. 

 Limestone is the most widely diffused of all rocks, and contains 

 12 per cent, of carbon. Petroleum consists largely of carbon, and 

 there is a far larger accumulation of carbon in the limestone rocks 

 of the United Kingdom than in all the Coal-measures the world 

 contains. A range of limestone rock 100 miles in length, by 10 

 miles in width, and 1000 yards in depth, would contain 743,000 

 million tons of carbon, or sufficient to provide carbon for 875,000 

 million tons of petroleum. Deposits of bituminous shale have also 

 limestone close at hand ; e.g. coral-rag underlies the Kimmeridge 

 clay, which is more or less saturated throughout with petroleum, 

 and it also underlies the famous Black-shale of Kentucky, which is 

 extraordinarily rich in oil. 



II. The evidence of volcanic action in close proximity to petroleum 



