184 DESCRIPTIVE MINERALOGY. 



peculiar odour, however, is perceptible for a considerable distance from the spring.* The 

 substance is collected by skimming it from the fountain, and is used as an external applica- 

 tion in various diseases. Indeed so highly was it prized by the Indians, that a mile square 

 around the spring has been reserved for the Senecas. The article, sold under the name of 

 Seneca oil in the Eastern and Northern States, is said to be obtained from Oil creek m 

 Venango county, Pennsylvania, where it is not only more abundant, but more pure than at 

 the Cuba spring. 



Mr. Hall remarks, that the rocks at Rockville are all highly bituminous ; the sandstone so 

 much so, that it scents the clothes of the workmen ; and the water of the springs, though 

 clear, has the taste of bitumen. 



Cattaraugus County. There is a petroleum or oil spring in the town of Freedom, similar 

 in many respects to that of Cuba in the adjoining county ; but its diameter is somewhat less, 

 and the quantity of petroleum which rises to the surface is proportionably the same. It is 

 situated in a bluish aluminous shale similar to that found on the Cattaraugus creek, above 

 Zoar. This shale, which is about twenty-five feet in thickness, rests on a sandstone, which 

 is more highly bituminous than any other rock in the district. In making an excavation of a 

 little more than fourteen feet, about six yards from the spring, pure, glossy, black petroleum, 

 mingled with water, gushed up with great violence. A large quantity of oil was daily 

 removed from this for some time, but afterwards the quantity of oil diminished both in the 

 new and the old springs, and it is now less than it was at the first settlement of the country.! 

 Chautauque County. The sandstone which occurs at Laona, near Fredonia, has a strong 

 bituminous odour, and not unfrequently contains cavities filled with a liquid resembling petro- 

 leum. Thin seams of bituminous coal, or of what seems rather to be indurated petroleum, are 

 found alternating with the strata of slate found at Fredonia and in its vicinity, especially on 

 llie shores of Lake Erie. The remarkable evolutions of carburetted hydrogen for which this 

 i.-2gion is so celebrated, are undoubtedly to be ascribed to the decomposition of these bitumi- 

 nous substances. 



Erie County. Springs of petroleum often rise in the shales of this county, especially on 

 t.he Cauquaga creek. These shales are often so highly charged with bitumen as to burn freely 

 when ignited. 



Seneca County. Petroleum is found floating on the surface of Seneca lake, whence the 

 name of Seneca Oil, by which it is commonly known. It is also frequently found on the sur- 

 face of springs in various parts of the county. 



* Vanuxem, New-York Geological Report, 1837. f E. N. Horsford, Nem-Yoric Geological Reports, 1840. 



