Attraction, n.

This power, principle or tendency in bodies to unite, is distinguished by philosophers into attraction of gravity or gravitation, which extends to a sensible distance, such as the tendency of the planets to the sun, or of a stone, when raised in the air, to fall to the earth, and of which kind is the attraction of magnetism, and of electricity; and into attraction of cohesion, or that tendency which is manifested between small particles of matter, at insensible distances, or near the point of contact, to unite them in coherence. The attraction of gravity is supposed to be the great principle that confines the planets in their orbits. Its power or force is directly as the quantity of matter in a body, and inversely as the square of the distances of the attracting bodies. Contiguous attraction is that which is exerted between minute particles or atoms, at insensible distances. When this principle unites particles of the same kind, it is called affinity of aggregation, cohesive affinity or cohesion. When it operates on dissimilar particles, producing union, it is distinguished as heterogeneous, and called chimical attraction or affinity.