— The spleen, from being an organ common to the human frame, must have an allotted service to supply; although considered useless by some, to all of unknown utility, it may be a lateral channel of arterial blood direct from the heart, to supply the vessels lying in a portion of the body not traversed by the arteries belonging to the great arterial system; those of the diaphragm first; thence through the umbilical cord to the fetus, in which the circulation is indispensable, from being the only means of conveying and dispersing throughout the body, in the absence of respiration, the minus-pressure matter which the organism of the fetus requires to promote the several functions, without which life would become extinct if commenced. In this supply of motion promoting elementary matter, consists all that can be considered aeration of the blood, and all that the blood of both the fetus and the adult requires, or can possibly receive. In the chirping chick, while within the yet unbroken shell, aeration is prevented by incubation of the mother bird; but the arterialising elementary matter is amply provided within the larger, apparently empty, end of the shell. To keep out electric matter, which would exclude the blood-moving medium, is the object of the hen sitting on the eggs, and oven-hatching is effected on the same principle.
How the Diaphragm Is Raised.
— The diaphragm cannot rise of itself, and has no self-acting, self-lifting nerves or muscles, all flesh being composed of inert atoms. The rise is proof positive that pressure is greater on the posterior than anterior surface of the membrane, and the unchanged normal pressure beneath indicates reduced pressure above; the latter is promoted by minus-pressure matter imparted by the splenic blood to the diaphragm, while passing through the vessels of the diaphragm. This arterialising matter being highly evanescent, escapes from the diaphragm and upwards, and during the escape mitigates the pressure, intercepts it in some degree from the superior surface; then, by the normal pressure beneath, the rise of the diaphragm is effected. As the escape, or separation, is becoming complete, the equilibrium is being restored, and the diaphragm depressed to the normal level. If this be not the rationale of diaphragmatic motion, it will be little improved by the substitution of muscular energy, leverage, or muscular vitality, while leaving out muscular inertia, which should not be omitted, but included, in accounting for every muscular action and motion.
CORRELATIVE ELEMENTS.
Any pair of the general elements, the interstices of one of which are the only interstices for receiving and retaining the atoms of the other, or that can be occupied by the atoms of any other of the general elements, such elements are correlatives.
Elementary co-relation is conspicuous in the opposite polarities of the loadstone, magnet, and crystals, and all bodies subject to polarization, which includes the animal frame. Similar co-relation is evinced between the galvanic fluids, those of the pile, and those named electricity; likewise between oxygen and hydrogen, the oxygenating element and nitrogen, acids and alkalies and all mutually neutralizing substances. Still it is not meant that all the general elements are so paired; doubtless, there are several ratios of size between the atoms of the different elements, for the purpose of multiplying variety among formations, the substance of which is of the same species throughout. Possibly the correlative principle gave rise to the ideal scale of chymical affinities, subsequently refined to affections of matter. Naturally, correlative elements will be found together, as are nitrogen and the imponderable element; also the magnetic fluids common to iron.
MAGNETISM.
Were attraction a property of the atomic substance of the loadstone, it could be neither transferable, receivable, nor liable to be destroyed by fire. A magnet is a work of art, the substance is inert, it can no more attract than think. Magnetism is an accident of matter; it consists in the correlatives of an iron bar having become separated, and drawn one to each end of the bar: separation and transition to the extremities of the bar, are what the rubbing on the poles of the loadstone effects.