uses and applications of petroleum have been immensely and wonderfully extended. The discovery of the American beds of petroleum and the application of industrial processes of distillation to them have been the beginning of a new industry, and of largely extended researches in all countries. Leopold von Buch (1801), who seems to have been the first to discuss the origin of the natural hydrocarbons scientifically, supposed that they were of animal origin. Violet d'Aoust, in 1814, believed them to be of the same origin as the rocks with which they were associated, native eruptive products, the resultants of causes still unknown; and repeated this opinion ten years later. Puvis thought, in 1836, that bitumen penetrated the rocks, according to their porosity, after their formation. Rozet, in 1836, thought that the bitumen of Pyrimont was sublimed from the depths of the globe through a crack that marked the direction of the formation, and was condensed in the porous rocks. Millet, in 1840, thought the same bitumen was derived from the decomposition of accumulations of vegetable matter, and ran down through the rocks. Itier, in 1839, supposed that the bitumens of the Jura were derived from the adjacent bituminous schists, which were full of vegetable fossils. Daubrée, in 1850, believed that the mode of their formation was similar to that of coal, but admitted the possibility of their having been derived from mineral synthesis. These views and the theory of volcanic origin have been reiterated in various modified shapes by other authors. M. Lartet published, in 1866, a valuable study of the geological relations of the bituminous deposits of the region of the Dead Sea.
When the mineral oils of the United States had become a prominent subject of attention, Mr. Leo Lesquereux made an elaborate discussion of them in the form of a letter to Liebig, in 1865, in which he gave his reasons for supposing that they were the products of the decomposition of marine plants. Dr. Sterry Hunt about the same time concluded, from an examination of the petroleum beds of Kentucky, that the oil, or the organic substances from which it was produced, were deposited in the strata where the oil is found contemporaneously with the formation of the rock. Mr. Orton, after a thorough study of the petroleum of the Trenton limestone of Ohio, published his conclusion in 1884, that it was of organic origin—derived from the decomposition of vegetable and animal matter. The supply could not be renewed, and was therefore not inexhaustible. It was probably produced at the ordinary temperature and not by distillation.
Some authors, assuming that these hydrocarbons are derived from the decomposition of organic matter, have tried to imagine the manner of the process, and to distinguish between it and ordinary or putrefactive decomposition.
