142 Chi the Lnxv of Sjjrnmetri/, 



all the others are involved. That mobility is implied in the idea 

 of elasticity is obvious. That there could not be mutual elasticity 

 without mutual impenetrability, is no less certain. Heat, in like 

 manner, if it be a property of matter at all, can only be explain- 

 ed on the supposition, that it is the action of atomic elasticity. 

 Luminousness is generally agreed to be a phenomenon depend- 

 ing on motions taking place in an elastic medium ; and, with re- 

 gard to attractability, no attempt was ever made to explain it, 

 otherwise than by having recourse to elasticity, as an efficient 

 cause in the media producing it. Elasticity, therefore, is the 

 great comprehensive property of matter, to which very many 

 phenomena in the present state of science is to be traced, and 

 into the idea of which almost all the other properties of matter 

 enter. But whether the reader assent to these remarks or no, 

 to this certainly all will assent, that elasticity is a most important 

 and paramount property of matter. 



This granted, in order to see that any group of particles act- 

 ing upon each other must ultimately settle in relative positions, 

 the most symmetrical which, in the existing circumstances of the 

 case, they possibly can assume, it is only necessary to consider 

 for a moment what phenomena must ensue in a group of elastic 

 particles, made to act upon each other, and, though free to move 

 about, yet prevented from separating beyond the sphere of each 

 other's action. The obvious tendency of the property of elasti- 

 city, in such circumstances, is to effect a balance of motion in 

 the opposite regions of the whole group ; and this, it is plain, can 

 only be done by giving rise to a balance in the quantity of mat- 

 ter in opposite or symmetrical positions. That the positions of 

 greatest relative symmetry can alone be the positions of equili- 

 brium and quiescence in elastic bodies, (their particular forms 

 and tendencies of attachment neglected), results from the very 

 nature of motion ; for motion ever tends to persevere in a right 

 line ; and therefore, if embodied in a deformed line of particles, 

 and forced to pursue a course along them, it must ever tend to 

 rectify that line; or if made to circulate in a continuous but 

 deformed chain of particles, it must ever tend to reduce it to a 

 circle. In one word, if embodied in any group of particles 

 whatever, it must tend to arrange them as a spherical mass_> or 

 a system of radii of equal length, surrounding that particle 



