The discovery of oil springs and wells in various parts of our country has excited of late the interest and attention of the scientific as well as of the speculating world. That there stould be liuch vast accumulations of mineral oil within the bowels of the earth, stored ap for tiea and to be obtained by merely tapping, is in sa!f onli of tho moit fl'IHlfkshla gMlo/ionl disMveriM of rha dill' , To SfI'oani for orlgi!! of ?ormstfo!l of this : oil has led to many wild and visionary theories, among which we cite the following: That the oil was an original creation of the Almighty architect of the globe, and, ot course, no more wonderful than any other of His creations; that the oil is a drainage from the coal beds; and your correspondent (page 211 of the current volume of your journal) gives another, which is, that the oil of Westerp. Peansylvania is the condensed gMes thrown off in changi.g the coal of Eastern Pennsylvania into anthracite. With the view of throwing light upon this subject, and to gil'e what I conceive to be the true explanation ef the phe^clUon, I ^1 lay down a few acknowledged principlilt ud Ole gln !I brief statement of the geo-Iggieal ^^Mtten til whlib coal, oil, bitumen and kindred hyd^^rboIl/l arc fond. ht. Coal and bitumen are of vegetable origin ; but bitumen is not confined to the vegetable kingdom; it may be found also in the animal. 2d. The vegetable matter may be either land plants or water plants. 3d. That, by cosmical chemistry (by this term we unde^^tand those ohemieal operations which take place spontaneously withi the bowels of the earth), vegetable matter may be converted into bitumen, bituminous coal, cannel coal, semi-anthracite and anthracite ; in a word, all the varieties of coal known to scientific and practical men. Vegetable fiber is composed of carbon, 36 parts ; hydrogen, 22 ; and oxygen, 22. Now, if from this formula we extract 3 equh-alents of carbon, 3 of hydrogen and 9 of carbonic acid, there will remain the precise formula of many of the coals. In this way vegetable fiber may be converted into carbon. Carbureted hydrogen (commonly called mars gas) is composed of carbon, 2 parts; hydrogen, 4. This gas is constantly escaping from bog lands and pools of stagnant water haying vegetable matter in the bottom; showing that there is decomposition of vegetable fiber going on, the proceeds of which are bi-earbureted hydrogen, instead of carbonic oxyd, as in the ordinary process of decomposition by combustion. 4th. Having shown how coal and bitumen may be derived from ligneous matter by the powers of Nature's chemistry, it is fair to infer that the same power is capable of forming mineral oil or petroleum. According to Dumas, petroleum is composed of carbon, 3 parts; hydrogen, 5. These elements may all be derived from the decomposition of ligneous fiber. This inference is quite a certain conclusion, when we consider that all the rocks from which flows mineral oilare rich in bitumenconstituting what geologists call JitaminoMs shale. 5th. We have a similar exhibition of the power of cosmical chemistry forming compounds from original elements in the lime springs of Onondaga county, N. Y. No beds of rock salt have ever been found in the Onondaga salt group of rocks, but the elements of muriate of soda arc distributed through the entire mass of the saliferous shales, and need but the presence of water to combine them, and carry them into reservoirs beneath the surface by the simple act of percolation or drainage of the rocks. 6th. In accounting for the formation of anthracite, it is not necessary to take into the elements of our theorizing the acthm of a high heat to change bituminous coal into anthracite. Heat is capable of so doing. In North Carolina, a vein of trap cuts through bituminous coal. Now, trap, all admit, was once fluid through high heat, and where it is in contact with the coal it has changed it into anthracite. But other chemical agencies are equally able to effect this chemical transmutation of the relative proportions and combination of hydrogen and carbon. Professor E. Emmons has shown before the Philadelphia Academy of Natural Sciences, that cosmical chemistry with low heat has been the efficient cause of the metamorphism of bituminous into anthracite coal. I wiU now proceed to state, in reference to the tlieory of your correspondent, that it is not necessary to suppose an evaporation into air of the gaieoas products hydrogen and carbonattending the metamorphism of bitumillous poal, and their subsequent condensaFon and deposition in distant gMgraphical localities, to flc-donlit for th e geololiillAI (jf miBilr/!.l PUS fts4 the ' They are formed fram the material existing in the shales holding the oils, and this matenal was derived from vegetation (marine or land) and animal matter, existing at the time the shales were deposited. Oils, bitumen and coal are not confined to the carboniferous, but are found in all the sedimentary strata older and later than the coal. I give a condensed tabular view of the various geological formations acknowledged by American geologists, which y,ield cither of the above-mentioned hydro-carbon products, proceeding from the reeent to the ancient, and giving localities of their deposition. Tai/e if Geological Fo^-^jations in descending mder. wif/i Geogra/^'cai Posid'onj oj COa/, BitumeH and Gas. By inspection of this table, at a glance the locality of oils can readily be seen, and it will be observed that they are found below the coal. In these localities and positions are found the oils of Meadville, Titusville, Kinzua, Cuba, Richmond, Mecca, and others in the northeast of Ohio, northwest of Pennsylvania aml. southwest of New York. They are all in the devonian. The following diagram will illustrate their geological horizon :The oil and gas springs of Kanawha, Va.; Coshocton and Yellow Creek, Ohio; Kiskiminitas, Pa., and other localities south of the northern out croj* of the carboniferous, are in the true coal measures. The following section shows the geological relations of the strata across the coiiiit^^ from tlic gas springs of Ontario county, N. Y., to the oil wells of PennsA-lv.a-nia; the inclination gives the dip of the strata south-warf: A is the carboniferous. B, the devonian (upper), containing oil sjn-ings. C, the devonian (lower), containing pas spring. f', wella in the valley of the Allegheny and its tribu-yariee, &l!/lIr"'ing btloIV ths 6l nd Hanid oil, % P, p.