NUMBER 1 (See page 7)
PROFESSOR SILLIMAN'S REPORT ON PETROLEUM
[From "The Early and Later History of Petroleum," by J. T. Henry, pages 38-54.]
Messrs. Eveleth, Bissell and Reed.
Gentlemen:—I herewith offer you the results of my somewhat extended researches upon the rock-oil, or petroleum, from Venango County, Pennsylvania, which you have requested me to examine with reference to its value for economical purposes.
Numerous localities, well known in different parts of the world, furnish an oily fluid exuding from the surface of the earth, sometimes alone in "tar springs," as they are called in the Western United States; frequently it is found floating upon the surface of water in a thin film, with rainbow colours, or in dark globules, that may, by mechanical means, be separated from the fluid on which it swims.
In some places wells are sunk for the purpose of accumulating the product in a situation convenient for collection by pumping the water out. The oil exudes on the shores of lakes and lagoons, or rises from springs beneath the beds of rivers. Such are the springs of Baku, in Persia, and the wells of Amiano, in the duchy of Parma, in Italy. The usual geological position of the rocks furnishing this natural product is in the coal measures—but it is by no means confined to this group of rocks, since it has been found in deposits much more recent, and also in those that are older—but in whatever deposits it may occur, it is uniformly regarded as a product of vegetable decomposition. Whether this decomposition has been effected by fermentation only, or by the aid of an elevated temperature, and distilled by heated vapour, is perhaps hardly settled.
It is interesting, however, in this connection to remember that the distillation, at an elevated temperature, of certain black, bituminous shales in England and France has furnished large quantities of an oil having many points of resemblance with naphtha, the name given to this colourless oil, which is the usual product of distilling petroleum. The very high boiling point of most of the products of the distillation of the rock oil from Venango County, Pennsylvania, would seem to indicate that it was a pyrogenic (fire-produced) product.
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