CORONA

, in Optics, a luminous circle, usually coloured, round the sun, moon, or largest planets. See Halo.

Corona Borealis, or Septentrionalis, the Northern Crown or Garland, a constellation of the northern hemisphere, being one of the 48 old ones. It contains 8 stars according to the catalogue of Ptolomy, Tycho, and Hevelius; but according to the Britannic Catalogue, 21.

Corona Australis, or Meridianalis, the Southern Crown, a constellation of the southern hemisphere, whose stars in Ptolomy's catalogue are 13; in the British Catalogue, 12.

CORPUSCLE the diminutive of corpus, used to express the minute parts, or particles, that constitute natural bodies; meaning much the same as atoms.

Newton shews a method of determining the sizes of the corpuscles of bodies, from their colours.

CORPUSCULAR Philosophy, that scheme or system of physics, in which the phenomena of bodies are accounted for, from the motion, rest, position, &c, of the corpuscles or atoms of which bodies consist.

The Corpuscular philosophy, which now flourishes under the name of the mechanical philosophy, is very ancient. Leucippus and Democritus taught it in Greece; from them Epicurus received it, and improved it; and from him it was called the Epicurean Philosophy.

Leucippus, it is said, received it from one Mochus, a Phenician phisiologist, before the time of the Trojan war, and the first who philosophized about atoms: which Mochus is, according to the opinion of some, the Moses of the Scriptures.

After Epicurus, the corpuscular philosophy gave way to the peripatetic, which became the popular system. Thus, instead of atoms, were introduced specific and substantial forms, qualities, sympathies, &c, which amused the world, till Gassendus, Charleton, Descartes, Boyle, Newton, and others, retrieved the corpuscularian hypotheses; which is now become the basis of the mechanical and experimental philosophy.

Boyle reduces the principles of the corpuscular philosophy to the 4 following heads.

1. That there is but one universal kind of matter, which is an extended, impenetrable, and divisible substance, common to all bodies, and capable of all ferms. —On this head, Newton sinely remarks thus: “All things considered, it appears probable to me, that God in the beginning created matter in solid, hard, in penetrable, moveable particles; of such sizes and figures, and with such other properties, as most conduced to the end for which he formed them: and that these primitive particles, being solids, are incomparably harder than any of the sensible porous bodies compounded of them; even so hard as never to wear, or break in pieces: no other power being able to divide what God made one in the first creation. While these corpuscles remain entire, they may compose bodies of one | and the same nature and texture in all ages: but should they wear away, or break in pieces, the nature of things depending on them would be changed: water and earth, composed of old worn particles, of fragments of particles, would not be of the same nature and texture now, with water and earth composed of entire particles at the beginning. And therefore, that nature may be lasting, the changes of corporeal things are to be placed only in the various separations, and new associations, of these permanent corpuscles.”

2. That this matter, in order to form the vast variety of natural bodies, must have motion in some, or all its assignable parts; and that this motion was given to matter by God, the creator of all things; and has all manner of directions and tendencies.— “These corpuscles, says Newton, have not only a vis inertiæ, accompanied with such passive laws of motion as naturally result from that force; but also are moved by certain active principles; such as that of gravity, and that which causes fermentation, and the cohesion of bodies.”

3. That matter must also be actually divided into parts; and each of these primitive particles, fragments, or atoms of matter, must have its proper magnitude, figure, and shape.

4. That these differently sized and shaped particles, have different orders, positions, situations, and postures, from whence all the variety of compound bodies arises.

CORRIDOR. See Coridor.