1857.] The gravitating Force. 449 



vitating action of one particle and many. The particle A will 

 attract the particle B at the distance of a mile with a certain 

 degree of force ; it will attract a particle C at the same distance 

 of a mile with a power equal to that by which it attracts B ; if 

 myriads of like particles be placed at the given distance of a 

 mile, A will attract each with equal force ; and if other par- 

 ticles be accumulated round it, within and without the sphere 

 of two miles diameter, it will attract them all with a force vary- 

 ing inversely with the square of the distance. How are we to 

 conceive of this force growing up in A to a million- fold or more ? 

 and if the surrounding particles be then removed, of its dimi- 

 nution in an equal degree ? Or, how are we to look upon the 

 power raised up in all these outer particles by the action of A 

 on them, or by their action one on another, without admitting, 

 according to the limited definition of gravitation, the facile ge- 

 neration and annihilation of force ? 



The assumption which we make for the time with regard to 

 the nature of a power (as gravity, heat, &c.), and the form of 

 words in which we express it, i. e. its definition, should be 

 consistent with the fundamental principles of force generally. 

 The conservation of force is a fundamental principle ; hence 

 the assumption with regard to a particular form of force, ought 

 to imply what becomes of the force when its action is increased 

 or diminished, or its direction changed ; or else the assumption 

 should admit that it is deficient on that point, being only half 

 competent to represent the force ; and, in any case, should not 

 be opposed to the principle of conservation. The usual defi- 

 nition of gravity as an attractive force between the particles of 

 matter VARYING inversely as the square of the distance, whilst 

 it stands as a full definition of the power, is inconsistent with 

 the principle of the conservation of force. If we accept the 

 principle, such a definition must be an imperfect account of 

 the whole of the force, and is probably only a description of 

 one exercise of that power, whatever the nature of the force 

 itself may be. If the definition be accepted as tacitly in- 

 cluding the conservation of force, then it ought to admit that 

 consequences must occur during the suspended or diminished 

 degree of its power as gravitation, equal in importance to the 

 power suspended or hidden ; being in fact equivalent to that 

 diminution. It ought also to admit, that it is incompetent to 



