The range of the yellow deposit, supposed to belong to the old red, is well defined; it commences on the northern slope and face of Salisbury Crags, and covers nearly the whole eastern side, depending to the Hunter’s Bog. The same series of beds, readily distinguished by their reddish hue, train round by Samson’s Ribs, thence proceeding by St. John’s Hill, Heriot’s Hospital, Burntsfield Links, they bear toward the New Cemetery on the estate of Grange. The beds here, exposed in several quarries, consist of an alternating series of marls, concretionary limestone, and sandstone, similar in all their lithological characters to the deposits of Dura Den and Glenvale. Not a fragment, indeed, of scale or organism has yet, so far as we know, been detected in the locality now defined, so as unequivocally to determine the position of the group in question. But is not the absence of the fossil test as fatal to its connection with the carboniferous series? while, considering its remote geographical distance from the undisputed domain of the new red, and its proximity to a surrounding belt of the true silurian, flanked with the old red, the presumption is that the deposit will yet be classed with the upper or yellow sandstone division of the devonian family. Still we merely indicate an unpresuming judgment, leaving it to so much gifted local research to confirm or disprove the correctness of the proposed classification. III. The Mid Lothian coal-basin, so rich in minerals, forms part of the great carboniferous valley of Scotland, and may be considered as simply an extension of the coal-field of Fifeshire, the metals dipping on both sides toward the middle of the Frith. The out-crop rises toward the Lammermuirs and the Pentlands.—The area occupied by the coal-measures includes a space of about eighteen miles in length, by twelve in breadth. The series of beds composing the formation, are nearly five thousand feet thick, or about a mile in depth from the upper to the lower strata, and the whole fractured and dislocated in every part of the field. There are fifty-two slips, indeed, enumerated by the miners, which occasion a depression toward the north to the extent of 5,196 feet; the metals are again raised by a series of thirty-seven slips to the height of 2,412 feet; thereby causing a change of relative level in the strata, corresponding to the altitude of the highest points in the Lammermuir range, namely, 2,757 feet. The disturbances above and below thus approximate to each other. Have they been directed and modified by the same agencies, the silurian group rising higher and higher as the carboniferous subsided into the depressions occasioned by the evolution of the igneous matter? The Bass, North Berwick Law, and Arthur’s Seat, are the products of the change, though indeed these scattered points of igneous rock on the surface can give no idea of its subterranean extent, since basalt and greenstone are met with at unvarying depths in a great