Page:Popular Science Monthly Volume 58.djvu/233

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THE

POPULAR SCIENCE

MONTHLY

 

JANUARY, 1901.




ASPHALTUM FOR A MODERN STREET.
By S. F. PECKHAM.

ASPHALTUM is the solid form of bitumen, as it occurs in nature. It has been known to man from prehistoric times. The word is said to be derived from privative, and σφάλλο 'I cause to slip.' It, therefore, signifies a substance that prevents one from slipping, and was applied to the solid forms of bitumen that soften in the sun. This substance was not rare in so-called Bible lands, embracing the Valley of the Euphrates, the table lands of Mesopotamia and the Valley of the Jordan. It was of frequent occurrence along the shores of the Dead Sea, and was gathered and sold in the caravan trade that passed through the land of Moab and Petrea into Egypt, where it was used in the preparation of mummies.

During the Middle Ages, asphaltum appears to have found but few uses, and is seldom mentioned. The words asphaltum, petroleum and naphtha appear to have been used with different meanings, and also interchangeably or synonymously; yet the words were generally used to signify a thing that was located and defined by further description, so that the bitumen of the Dead Sea was recognized as asphaltum or solid bitumen.

Within the present century, however, both words and definitions have been more exact. As other and slightly differing material was obtained that in some respects resembled coal, it was claimed that some of the deposits of bitumen were beds of coal, and this claim led, about 1850, to important litigation, in which, as experts, scientific men gave very conflicting testimony, one party claiming that the material of certain deposits was asphaltum, and the other that it was coal. It was finally decided that the material—the albertite of New Brunswick—was not coal, and, therefore, did not belong to the Crown. At about this time a deposit occurring in West Virginia, since known as Grahamite, which, in appearance, is much more like splint coal than albertite,