ATTRACTION

From Agepedia

ATTRACTION ; the tendency, as well of the parts of matter in general, as of various particular bodies, to approach each other, to unite, and to remain united; sometimes, also, the power inherent in matter, exerting itself at the moment of approach. Experience teaches that this property is common to all matter. Even liquids cohere in their parts, and oppose any endeavor to separate them. The minute particles unite into drops; drops, if they are brought in contact, into large masses. Fluids attach themselves to solid bodies, particularly to such as have veiy smooth surfaces, as to glass: they rise up of themselves in fine tubes (see Capillary Tube), &c. Every body tends to the earth, and, if raised from its surface, falls back to it again. The plumbline, which is usually vertical, takes an oblique direction in the vicinity of high mountains ; the sea tends to the moon; the moon itself is constantly drawn towards the earth; the earth and the other planets, towards the sun. The heavenly bodies are continually subject to the simple lawof mutual attraction. The Grecian naturalists speak of attraction; Copernicus and Tycho likewise admit it; Kepler's bold and comprehensive mind first hazarded the assertion that it must be universal and mutual in all bodies; Des Cartes sought to banish it entirely from natural philosophy, as one of those occult powers which he did not acknowledge; but Newton adopted it, and determined its laws, after many years of accurate observation. Fruitless attempts have been made to explain it. The phenomenon of attraction is exhibited, either in bodies that are at perceptible distances from each other, and is then called gravitation; or in bodies at insensible distances, taking place between their surfaces, when it is adhesion; or uniting their component parts, when it is cohesion, (q. v.) We cannot enumerate all the particular subdivisions 'of attraction, but the most important are those of chemical affinities (q. v.), of magnetic and electric attractions, &c. (Respecting these, see the particular articles.) The best work on the attraction of the heavenly bodies is Newton's Philosoph. Natural. Principia Mathematica. On the attraction which mountains exert on the plumbline, see von Zach's & Attraction des Montagnes et ses Ejfets sur les Fits a Plomb (Avignon, 1814, 2 vols.) Kant's Metaphys. Elements of Natural Science (3d ed. Leips., 1800) treats of the nature of attraction. (For further information on the subject of attraction, see the article Mechanics.)