Penny Blood: Serial Sensation and Working-Class Entertainment — page 223: what you’re looking at

Machine-transcribed from the original scan — historical spelling and the odd misread are preserved.

ey yA 2 hn a, te pane é Ce mes € 206 COMPRESSION AND VOLCANIC ACTION. (cu. xv. ally denuded down, and the material carried to the shore margin again, and there accumulating, sinking, and being again pressed towards the ranges, would cause a kind of circulation of rock from the coast-line inland, and back again by way of the surface. Since by this means every part would in its turn be subjected to atmospheric action, the more soluble basic constituents would be carried out to sea, and it is possible that it may be to this cause that the lesser density of the continental crust may be owing, even although the continental rocks have these con- stituents to some extent continually restored by the intrusions of the magma from below’. It has been ascertained that in the deeper parts of the ocean, from 2700 fathoms and more, the dredge invariably brings up a fine red clay, consisting of silica, alumina, and oxide of iron; and everywhere contaiing nodules of the peroxide of manganese*. It matters not what the mode of transference and deposit of this clay may be, whether directly as sediment, or indirectly, as believed to be the case, from the insoluble remains of animal exuvir, for what is material to our present argument is, that these heavy minerals, iron and manganese, are accumulating over the floor of all the deeper parts of the ocean, thus rendering the mean density of the crust increasingly greater there, and necessarily abstracting these substances from elsewhere, which can be nowhere except from the continental areas, and diminishing their density by that means. The relation between the amount of compression, and the quantity of lava injected into and solidified in the fissures, is easily found. Referring to the figures on page 46, suppose the tract, which before compression gave the rect- angular section ABCD, to be distorted by the opening of fis- sures. These will become partially or wholly filled with lava. The parts of them which do not become so filled, become filled ( with debris, forming veinstone, and this will be derived from | See an interesting paper on the stratified rocks considered with respect to the contributions which the internal parts of the globe have made towards them by M. Daubrée, ‘‘ Bulletin de la Société de France,” 2ce Série t. xxviir. p. 363. Séance du 7 Sep. 1871. @ ** Natare,” Vol. x1. p.116. Dec. 10, 1874. COMIC OOOKS.EO