Penny Blood: Serial Sensation and Working-Class Entertainment — page 113: what you’re looking at

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

96 FLUID SUBSTRATUM. [cH. VIII. The presence of so large a quantity of water substance in the deep-seated and molten rocks is still to seek. The following supposition is offered with considerable diffi- dence. It has been suggested by a paper lately read by Mr Mallet before the Geological Society’, although it will be apparent that it is not the same theory as Mr Mallet’s. That gentleman has pointed out the undoubted fact, that, if all the water upon the face of the globe were to be at the present moment con- verted into vapour, the pressure which it would exert at the earth’s surface would be the sanie as would be exerted by the present oceans, were they spread in an equable layer over the surface. He then enters into speculations regarding the tem- perature to which water might be raised under such pressure, and its effect upon rocky matter. Let us then revert to the far distant time when the tem- perature of the earth had fallen to that point, when the oxygen and hydrogen were first able to combine. The pressure, caused by the gravitation of the water substance formed from them, would have been that due to a layer of liquid water its exact equivalent. This would have been the same as the pressure of a column of an ocean somewhere about two and a half miles deep. ‘The water substance would at that time have been at far above its critical temperature, and possessed of great solvent power upon silicates and some other minerals. It may then be asked, Is it necessary to suppose that the rocky materials had already formed a solid globe, upon which this water substance was supernatant? Might not rather such substances as were soluble have been in solution with it, even to that depth at which the magma was succeeded by denser materials msoluble in super- heated water? If that were so, then as cooling proceeded a crust of rock would have been formed by crystallization at a certain level, and would have gradually extended downwards. But there may be even still remaining an intensely hot layer of original water-dissolved silicates, underlying the solid crust, ever in readiness to furnish the steam, gases, and ejectamenta of the volcano; and by the extravasation especially of the former of these to contribute to the contraction of volume of the globe. 1 «Quart. Journ. Geol. Soc.” Vol. xxxvr. p. 112. commiclsoolkks (CO) a ae of « ad - OR eee, 2 Ce oe eee Ce eee eee 5 PP. eee oe - a ———— AN, ee eee — a — | |