244 Notes on Vetroleum 



panying trap rocks, as at Quebec, Orleans Island, Point Levis, 

 and at Acton, presenting mamillary surfaces as noticed by 

 Vanuxem, which evidently show that it has once been semi-fluid. 

 This matter from the first two localities is completely infusible, 

 and iosoluble in benzole; it readily crumbles between the fingers 

 and gives a very black powder. When exposed to a high tempera- 

 ture it gives off" abundance of inflammable strong smelling vapors, 

 which condense into a tarry oil, and leaves a black residue, which 

 when heated slowly burns away, leaving only a trace of 

 ash. The volatile portion is equal to from 19.5 to 21.0 per cent. 

 The mineral from the Acton copper mine is much harder and less 

 friable, and approaches to anthracite in its characters. When 

 heated it gives off watery vapor without any bituminous odor. 

 Its loss by heat was 6.9 per cent, and the residue of ash was equal 

 to 2.2 per cent. 



An evidence of the presence of unaltered petroleum in 

 almost all the Lower Silurian limestones is furnished by the bitu- 

 minous odor which they generally exhibit when heated, struck or 

 dissolved in acids. In some cases petroleum is found filling cavi- 

 ties in these limestones,as at Riviere a la Rose(Montmorenci,)where 

 it flows in drops from a fossil coral of the Birdseye limestone, and 

 at Pakenham, where it fills the cavities of large orthoceratites in the 

 Trenton ; - from some specimens nearly a pint of petroleum 

 has been obtained ; it is also said to occur in the township of 

 Lancaster in the same formation. The presence of petroleum in 

 the Lower Silurian rocks of New York is shown in the township 

 of Guilderland near Albany, where according to Beck, considerable 

 quantities of petroleum are collected upon the surface of a spring 

 which rises through the Hudson River or Loraine shales. On the 

 Great Manitoulin Island also according to Mr. Murray, a petro- 

 leum spring issues from the TJtica state, and he has described 

 another at Albion Mills near Hamilton rising through the red 

 shales of the Medina group ; these have probably their origin in 

 the Lower Silurian limestones, which may in some localities prove 

 to be valuable sources of petroleum. 



In the Upper Silurian and Devonian rocks bitumen is much 

 more abundant; Eaton long since described petroleum as exuding 

 ffom the Niagara limestone, and this formation throughout Mon- 

 roe county in western New York is described by Mr. Hall as a 

 granular crystalline dolomite including small laminae of bitumen, 

 which give it a resinous lustre. When the stone is burned for 



I 



