CONVERSION OF PETROLEUM INTO GRAHAMITE 281 



great heat, fiying or baking the residuum out of bituminous shales and 

 forcing it in a pasty condition into the fissure, is entirely erroneous, since 

 the exhausted oil sand immediately under the region fully accounts for 

 the formation of the grahamite. 



Artificial production of Grahamite 



Then, too, Mr Walter P. Jenney, in the April number of the American 

 Chemist for 1875, describes how he produced in the laboratory a sub- 

 stance precisely similar in chemical composition to grahamite by passing 

 heated air through Pennsylvania petroleum for several hours, so there 

 can be no doubt of the derivation of grahamite from oil through the grad- 

 ual escape of its volatile constituents and the oxidation of the residuum. 



Origin of similar Substances 



A corollary from this conclusion would be that the albertite of Nova 

 Scotia has originated in the same way, and that gilsonite, uintaite, 

 wurtzilite, etcetera, are all forms of oxidized petroleum, Avhile Mr Diller, 

 of the United States Geological Survey, believes that the " pitch " coal 

 of Coos bay, Oregon, has also been derived from the same source. 



The wonderful deposit of asphalt on the island of Trinidad, South 

 America, has evidently originated from the upheaval, and the removal 

 by erosion of the cover of an immense pool of oil, thus subjecting the 

 oil to volatilization and oxidation. Had the clays, quicksands, and 

 gravels which cover the great deposit of petroleum at Baku, on the Cas- 

 pian sea, been elevated and eroded we should have a deposit of asphalt 

 there similar to that on the island of Trinidad. 



The graphites and other deposits of carbon in the Cambrian and pre- 

 Cambrian beds are simply sheet-like outflows of petroleum oxidized and 

 metamorphosed by atmospheric and igneous agencies respectively. 



Relationship between Grahamite and Petroleum Deposits 



Another corollary to be drawn from the conclusion that grahamite, 

 albertite, and similar substances are derived from petroleum would be 

 that in regions where these asphaltic deposits occur we may expect to 

 find accumulations of petroleum, provided the rocks remain in a normal 

 condition and are not too greatly disturbed. 



Bituminous Material from Brooks Well 



place and mode of occurrence 



The Whiske}^ Run oil-pool was developed in Ritchie county early in 

 1898, and it lies about as far north from Cairo as the grahamite deposit 



