Pressure being obviously the cause of planetary motion, so is it of all terrestrial motion. To produce atomic motion and transfer generally, it is necessary, only, that the atoms of the medium of space should be of less size than the minutest interstices in bodies.
A universal medium must be of universal service, (as would be conceived, were the universe involved in a medium of water,) to be in accordance with nature's economy: to keep the planets and matter in motion, to retain atoms together, and effect their separation occasionally, include the whole of action required by its service; more in this respect it cannot effect; nor is the common general procedure otherwise effected. Therefore in pressure, by the medium of space, consists the primum mobile: the beginning and end of all physical cause of action and of all physical effect.
Pressure is nothing assumed, hypothetic, or unproven, like attraction and gravitation,—the justly dethroned imbecile usurpers of the imperial chair of philosophy for ages past.
On barometric evidence alone, that pressure exists all round the globe is fully proved; and that it is indispensable to the maintenance of the existing general order, all must readily grant who reflect for an instant on the fatal consequences which the cessation of the general pressure, for only a few minutes, must cause. Hence it is no immediate question how the general pressure originated, how maintained, what the confining boundaries or point d'appui. Most likely it is the consequence of the motion of the planets themselves, surging through the ocean of space. As every performance of nature has some ulterior object in view, it is probable that the effect of the motion of a planet on the medium of space is tributary to the motion of another planet, and that the motion of the whole is a means of preventing the cessation of motion of any of the parts. Most likely the medium of space was not in a state of pressure at first; that planetary motion, however commenced, effected the state of pressure necessary for its continuance, and which would be useless beyond the precincts of planetary evolution: where pressure is not needed, of a certainty there is none. Hence the conclusion is warrantable, that the general pressure, however commenced, is maintained by not only the motion of the planets individually but in systems, through the ocean of space.
The earth may be said to swim through the medium of space, and to be soaked with it as a submerged sponge is with water, and the portion within the globe of the earth, is continuous with the like medium in space generally. By which all parts of the interior of the globe are under the general pressure equally as the surface, and all terrestrial bodies subject to its vicissitudes.
By such means, only, is the great earthquake to be accounted for on dynamic principles. Far as the subterraneous grumbling extends, the physical cause must be present, and in a state of force equal to the awful result. No pent-up air suddenly set free, or suddenly exploded gas,—both naturally forceless,—subject to attenuation and obstruction in the passage from the source—is competent to burst the globe and hurl whole cities into the engulfing chasm: nor is fire any assistant, judging from the absence of flame, smoke, cinders, and ashes. Dreadful as is the catastrophe, it is but a natural casuality and in perfect accordance with the laws of matter. An extraordinary rushing into the body of the earth of medium of space, preceded by an equal efflux of elementary matter atmospherically induced, are the cause and promoting means of the extraordinary, terrific phenomenon.
All things being under the general pressure, and elementary atoms of all sizes everywhere present, the interstices of bodies cannot remain empty. From all interstices being formed by spherical atoms, and the atoms of the medium of space the smallest, there are always interstitial spaces for medium of space to enter, pass through or remain within, and which is not insulated, but continuous with the outward source. Thus, has the medium of space access to every atom, and by the pressure from without, is enabled to act centrifugally within the body, as a kind of back-spring against each and the whole of its constituent atoms, to produce expansion, dissolution, and elementary dispersion according to the medium or circumstances in which the body may be placed. These general principles admit of repetition, in order, that, by repeated showing, to prove their validity, against others more generally known and adopted, although unfounded in nature, sense, or reason.
MINUS-PRESSURE MATTER.
Taking the maximum of pressure as a fixed quantity, or, as not being subject to increase, and assuming the degree to be not less than equal to the tenacity of steel, there must of necessity be means of mitigating the maximum, so that in the scale of descent every degree of force should be attainable; and more, to keep the equilibrium in a state of disturbance, without which all things must be, and remain in the rest of death. Were there no minus-pressure means, the solid, or perhaps aëriform state of matter would exist everywhere, and of motion there could be none. Such means for promoting motion are amply supplied, and without any addition of matter to the measured quantity sufficient for the formation of bodies and service of nature generally, in the elements themselves, of matter.