In taking this subject for a short review, let us inquire as to the meaning of these words and the use that has been, made of them. Here at the outset we are met with a considerable divergence of view and latitude, not to say looseness, of application.
In "Mineral Resources of the United States for I893," published by the United States Geological Survey at Washington, we find, on page 627, under the heading "Asphaltum," the following statement : " Under this generic name one finds included bituminous rock, sandstones and limestones impregnated with bitumen or asphaltum, free bitumens, either liquid, viscous or solid, containing little or no mineral matter, and, finally, mixtures in various proportions, more or less intimate, of bitumens with inorganic matter, or with both inorganic and organic matter." This certainly is a wide range of application for the term asphaltum. On the other hand, Ldon Malo and other French writers have sought to narrow its application to one class of natural product, as will be seen from the following quotation :
" Asphalt is a natural product, a bituminous limestone in wJ0ich carbonate of lime and pure mineral bitumen are most intimately combined by natural agency, the proportions varying from seven per cent. bitumen and ninety per cent. carbonate of lime to two per cent. bitumen and eighty per cent. carbonate of lime."# Similarly, Capt. F. V. Greene, in a paper read before the American Institute of Mining Engineers, October, i888, * A lecture delivered before the Mineralogical Section of the Brooklyn Institute, December 18, ~894 , and repeated at the Franklin Institute by request.
t " Twenty Years Practical Experience of Natural Asphalt." W.H. Delano. E. and F. Spon. I893.
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