144 THE POPULAR SCIENCE MONTHLY. 



Rue and Midler found naphthaline, C 10 H 8 , in Rangoon tar ; and, finai 



ly, a member of the anthracene series, C n H 2n 18 , has been found in the 



last products of the distillation of petroleum for paraffine-oil. It is 

 probably formed by destructive distillation of the petroleum, and has 

 been called thallene or viridine by Prof. H. Morton, who investigated 

 especially its fluorescent character. 



Petroleum undergoes alteration by evaporation of its lighter con- 

 stituents, leaving viscid or solid bitumen, containing more or less 

 paraffine ; by oxidation of some hydrogen, giving rise to ethylenes, 

 benzols, or naphthalenes ; and, by the additional absorption of oxygen, 

 forming true asphaltum. Of this latter class are the grahamite of 

 West Virginia and the albertite of Nova Scotia. The grahamite I 

 believe to have been altered before reaching its present level, for rea- 

 sons which cannot be given here. Mr. W. P. Jenney has made some 

 interesting experiments on the oxygenation of petroleum and the for- 

 mation of artificial oxygenated hydrocarbons resembling natural 

 products {American Chemist, April, 1875). 



Occurrence of Petroleum. It occurs in rocks of nearly all ages, 

 from the Lower Silurian up ; most abundantly in shales and sand- 

 stones ; also to some extent in limestones. Sometimes it impreg- 

 nates the whole stratum ; sometimes it collects in subterranean cavi- 

 ties and fissures. In the Rangoon and Caspian regions the oil oc- 

 curs near the surface in clayey soil, and collects in shallow pits. A 

 noted foreign locality is Ye-nan-gyoung, in Burmah, where the wells 

 are narrow shafts, 180 to 300 feet deep, and large enough for a 

 man to work in. The oil is drawn up with a bucket and windlass, 

 and as many as 1,000,000 barrels are annually obtained. In Persia 

 oil is largely found at Baku, on the west shore of the Caspian ; China 

 yields a small amount of oil; Japan has small and undeveloped 

 districts ; New Zealand, also, shows indications. In the Caucasus, 

 Russia, surface-wells have long been worked, and lately wells have 

 been sunk with great success. In Galicia, Austria, are wells yielding 

 largely ; and Alsace and Hanover have produced some oil. Petro- 

 leum has likewise been found in Peru, Ecuador, Southern Mexico, San 

 Domingo, Trinidad, and Nova Scotia, in small quantities. 



The petroleum district of Canada West is in Lambton, Bothwell, 

 and Kent Counties (II. E. Wrigley), and in Ontario. The average 

 production is not over 2,500 barrels daily. It occurs mainly in the 

 Corniferous limestone of the Lower Devonian, but is also found in 

 greater or less quantity in the Bird's-eye limestone of the Lower Si- 

 lurian, and the Lower Heldcrberg limestone of the Upper Silurian. 

 The cavities of Orthocerata in the Trenton limestone (Lower Silu- 

 rian) at Pakcnham, Canada, frequently hold small quantities of petro- 

 leum. In Canada East there is a petroleum district on the St. John's 

 River, not far from Gaspe Bay. 



In the United States oil is very abundant in Western Pennsylva 



