476 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



for the most part peculiar to the author, and in part now brought 

 forward for the first time. 



The third paper, from the pen of Sterry Hunt, was 



Ox THE SoUKCE AND OrIGIX OF PeTROLEUM, 



Of which we are able to give only a brief notice. The speaker 

 adverted to the history of certain views relative to petroleum. He 

 had shown in 1861, that the mineral oil of Western Canada was 

 indi<>-cnous in the corniferous limestone, wells sunk in the outcrop 

 of which have yielded, and still yield, oil in that region, and also 

 in Kentucky, according to Leslie. At that time (1861) he called 

 attention to the existence of petroleum in the limestones of the 

 Trenton group, and had, since then, in the Geology of Canada, in 

 1863, insisted upon these Lower Silurian oils as likely to prove 

 in some regions, of economic importance — a prediction verified by 

 the recent developments in the Lower Silurian strata of the Cum- 

 berland, in Kentucky, and the oil wells of the Manitoulin Islands, 

 which latter are sunk through the Utica and Trenton formation. 

 Another important point on which he had been the first to insist, 

 w^as that the accumulation giving rise to productive wells occur 

 along the lines of anticlinal folds, where the oil would naturally 

 accumulate in fissures or in porous strata, in obedience to well 

 known hydrostatic laws. This view, first insisted upon in a 

 lecture published in the Medical Gazette, for March, 1861, was 

 further developed in a paper on petroleum in the Canadian 

 Naturalist for July, 1861, and simultaneously by Prof E. B. 

 Andrews in Sillimaii's Journal. Since then this view, though 

 frequently opposed, is gaining ground, and according to Prof. 

 Andrews and Dr. Newberry, is sustained by all experience in the 

 oil fields of the United States, as it also is in Canada. This re- 

 mark applies to large accumulations and to flowing wells, but oil 

 may doubtless flow slowly from horizontal strata containing it. 



As to the origin of the petroleum. Dr. Hunt supposes that it is 

 indigenous in the two limestone formations already mentioned, 

 and that it may have from there risen and accumulated in over- 

 laying previous strata, or in fissures capped or sealed by impervi- 

 ous beds, such as Pennsylvania sand rock, or quartenary gravel 

 beds. 



He is inclined to think, however, that petroleum may also be 

 indigenous in certain sandstones of devonean or carboniferous 

 age, and referred to Lesley's observations to this eflect, closely 



