GEOLOGY. 287 



Hildreth, yielded from fifty to a hundred barrels yearly. It here 

 rises through the carboniferous strata, and, as elsewhere, is accompa- 

 nied by great quantities of inflammable gas. 



For many years bitumen in the solid form has been used for the 

 construction of pavements, for paying the bottoms of ships, and for 

 the manufacture of gas ; but in the liquid form of petroleum, its use 

 was mainly confined in Europe to medicinal purposes. Under the 

 names of Seneca oil and Barbadoes tar it had long been known and 

 employed medicinally by the native tribes of America. Its use for 

 burning, as a source of light or heat, in modern times has been 

 chiefly confined to Persia and other parts of Asia, although in former 

 ages the wells of the island of Zante, described by Herodotus, fur- 

 nished large quantities of it to the Grecian Archipelago, and Pliny 

 and Dioscorides describe the petroleum of Agrigentum, in Sicily, 

 which was used in lamps under the name of Sicilian oil. The value 

 of the naphtha annually obtained from the springs at Bakoum, in 

 Persia, on the Caspian Sea, was some years since estimated by Abich 

 at about six hundred thousand dollars, and the petroleum wells of 

 Rangoon, in Burmah, are said to furnish not less than four hundred 

 thousand hogsheads yearly. In the last century the petroleum or 

 naphtha obtained from springs in the duchy of Parma was employed 

 for lighting the streets of Genoa and Amiano. But the thickness, 

 coarseness, and unpleasant odor of the petroleum from most sources 

 were such that it had long fallen into disuse in Europe, when, in 1847, 

 the attention of Mr. 'Young, a manufacturing chemist of Glasgow, 

 was called to the petroleum which had just been obtained in consid- 

 erable quantities from a coal mine in Derbyshire, from which, by 

 certain refining processes, he succeeded in preparing a good lubri- 

 cating oil. This source, however, soon becoming exhausted, he 

 turned his attention to the somewhat similar oils which Reichenbach 

 and Selligue had long before shown might be economically obtained 

 by the distillation of coal, lignite, peat, and pyroschists. To this new 

 industry Mr. Young gave a great impetus, and, in connection with 

 it, attention was again turned to the refining of liquid and solid bitu- 

 mens, it being found that the latter by distillation gave great quanti- 

 ties of oils identical with those from petroleum. 1 



The oil-wells of the United States are, for the most part, sunk in 

 the sandstones which form the summit of the Devonian series, but the 

 oils of Western Virginia and Southern Ohio rise through the coal 

 measures which overlie the Devonian strata; while the principal 

 wells of Canada are situated much lower, and are sunk in the Ham- 

 ilton shales, which immediately overlie the Corniferous or Devonian 

 ' limestone. It is not impossible that in Ohio some of the higher strata, 

 such as the sandstone, were originally impregnated with bitumen, 



1 A few years ago, Mr. Young- testified in court, in England, to having manu- 

 factured by distillation from coal and sold in one year over 400,000 gallons of oil 

 for lubricating purposes. 



As yet, thotittcntion of refiners of coal-oil and petroleum in this country has 

 been confined to the products most readily derived from them, viz., burning 

 fluid, lubricating oil, and paraffiuc ; but the European manufactures have demon- 

 strated that the process may be profitably carried much farther, and that other 

 and more valuable secondary products may be derived from those first men- 

 tioned. 



