Crude petroleum was experimentally distilled in the United States in 1833 by Prof. Silliman (d.
The most productive are those of iron and zinc. Lignite is found in the department of Algiers and petroleum in that of Oran.
It consists in sinking a bore-hole, after the manner of a petroleum well, and letting in four pipes centrally arranged, the outer pipe being 10 in.
Treating the breeding-ponds with petroleum or similar preparations seems to be hardly applicable on a large scale, and in any case can only be a temporary expedient.
Bitumen and petroleum have been found; graphite is plentiful, and sulphur, salt, saltpetre and lime are also procured.
Extending from the south-west corner of the state through Greene, Washington, Allegheny, Beaver, Butler, Venango, Clarion, Forest, Elk, Warren, McKean and Tioga counties is the Pennsylvania section of the Appalachian oil-field which, with the small section in New York, furnished nearly all of the country's supply of petroleum for some years following the discovery of its value for illuminating purposes.
These, which go down to depths of 700 to 1700 ft., yield crude naphtha, from which the petroleum or kerosene is distilled; while the heavier residue (mazut) is used as lubricating oil and for fuel, for instance in the locomotives of the Transcaspian railway.
But it was not until the middle of the 19th century that its value as an illuminating oil became known, and not until 1859 was the first petroleum well drilled.
The region is a good one for general farming, and natural gas and petroleum are found in abundance in the vicinity.
While the subject of the testing of petroleum for legislative purposes has been investigated in Great Britain by committees of both branches of the legislature, with a view to change in the law, the standard has never been raised, since such a course would tend to reduce the available supply and thus lead to increase in price or deterioration in quality.