Natural paraffine is less abundant, and yet in places it occurs in considerable quantity. Asphalt is the common name for the solid residue from the evaporation and oxidation of petroleum; and large accumulations of this substance are known in many parts of the world, perhaps the most noted of all being that of the "Pitch Lake". of the Island of Trinidad; there, as everywhere else, the derivation of asphalt from petroleum is obvious, and traceable in all stages. The asphalts, then, have a common history in this, that they are produced by the evaporation and oxidation of petroleum. But it should also be said that they share the diversity of character of petroleums, and the term asphalt represents a group of substances of which the physical characters and chemical composition differ greatly in virtue of their derivation, and also differ from changes which they are constantly undergoing. Thus at the Pitch Lake in Trinidad, the central portion is a tarry petroleum, near the sides a plastic asphalt, and finally that which is of almost rock-like solidity. Hence we see that the solid residues from petroleum are unstable compounds like the coals and lignites, and in virtue of their organic nature are constantly undergoing a series of changes of which the final term is combustion or oxidation. From these facts we might fairly infer that asphalts formed in geological ages anterior to the present would exhibit characters resulting from still further distillation; that they would be harder and drier, i.e., containing less volatile ingredients and more fixed carbon. Such is, in fact, the case; and these older asphalts are represented by _Grahamite, Albertite_, etc., which I have designated as asphaltic coals. These are found in fissures and cavities in rocks of various ages, which have been more or less disturbed, and usually in regions where springs of petroleum now exist. The Albertite fills fissures in Carboniferous rocks in New Brunswick, on a line of disturbance and near oil-springs. Precisely the same may be said of the Grahamite of West Virginia. It fills a vertical fissure, which was cut through the sandstones and shales of the coal-measures; in the sandstones it remained open, in the shales it has been closed by the yielding of the rock. The Grahamite fills the open fissure in the sandstone, and was plainly introduced when in a liquid state. In the vicinity are oil springs, and it is on an axis of disturbance. From near Tampico, Mexico, I have received a hydrocarbon solid--essentially Grahamite, asphalt, and petroleum. These are described as occurring near together, and evidently represent phases of different dates in the same substance. I have collected asphaltic coals, very similar to Grahamite and Albertite in appearance and chemical composition, in Colorado and Utah, where they occur with the game associates as at Tampico. I have found at Canajoharie, New York, in cavities in the lead-veins which rut