On the Photogen Oils. 89 



parts of Europe ; and vast quantities of them are obtained in 

 Asia and America. The amount procured in some localities is 

 immense; four hundred thousand gallons of petroleum are 

 obtained annually in a small district round the town of Rainan- 

 gong, in the Burmese Empire : it is used by the Burmese as 

 oil for lamps, and, mixed with earth or ashes, for fuel. In 

 America also the produce is extremely abundant : eighteen 

 hundred gallons a day were afforded by one spring of petroleum, 

 which was found near Pittsburg, on the Allegany river, in 

 boring for salt. For a considerable time the wells in the valley 

 of the Mississippi yielded daily ten or twelve barrels of the 

 crude oil each, but their product was observed to diminish 

 according as additional wells were sunk in the neighbourhood. 

 Fifty thousand gallons are obtained each day in the United 

 States. The oil region there reaches from the 65th to the 

 128th degree of longitude west of Greenwich. Yery large 

 quantities are found also in Canada : the Spouting wells of that 

 locality gave at first an abundant supply, and it is supposed 

 that three hundred thousand barrels of the crude oil have 

 already been obtained from them; but one-half was wasted, 

 from the mode of managing the wells being very imperfect, 

 and from its being extremely difficult to control them when 

 they had once been tapped. In Canada, as in the United 

 States, the supply, however great, appears to be limited; for 

 the product of the Spouting wells — the chief source of petroleum 

 there — has already fallen from twelve thousand to four hundred 

 barrels a day, twenty-eight out of the thirty wells having ceased 

 to yield any ; and, as we learn from the most reliable authorities, 

 when a pump is used, little besides salt water is obtained from 

 them. Nor, although the oil region would appear from the 

 geological conformation to extend through the whole peninsula 

 of Upper Canada, has much success attended a search for oil 

 beyond the limited area of two miles square, within which the 

 wells may be said to be confined. 



Rangoon tar, which is perhaps the most abundant of all the 

 native naphthas, contains a large quantity of paraffine a substance 

 which, as is well known, is manufactured into the most beau- 

 tiful candles. When this tar is subjected to distillation . at a 

 temperature of 212 degrees, eleven per cent, of fluid hydro- 

 carbons, containing no paraffine, passes over; but as the tem- 

 perature is raised the amount of the distillate diminishes, while 

 that of the paraffine increases. At temperatures between 320 

 degrees and the fusing point of lead the products begin to 

 solidify on cooling, and their paraffine may be separated by 

 pressure. In the last stage, when the heat has become very 

 considerable, pitch-like substances pass over ; and after the 

 process is finished, four per cent, solid matter remains in the 



