1857.] On the gravitating Force. 447 



definition, if taken in an absolute sense, " varying inversely as 

 the square of the distance," to be in direct opposition to it ; 

 and it becomes my duty, now, to point out where this contra- 

 diction occurs, and to use it in illustration of the principle of 

 conservation. Assume two particles of matter, A and B, in free 

 space, and a force in each or in both by which they gravitate 

 towards each other, the force being unalterable for an un- 

 changing distance, but varying inversely as the square of the 

 distance when the latter varies. Then, at the distance of 10, 

 the force may be estimated as 1 ; whilst at the distance of 1, 

 i. e. one-tenth of the former, the force will be 100: and if we 

 suppose an elastic spring to be introduced between the two as 

 a measure of the attractive force, the power compressing it will 

 be a hundred times as much in the latter case as in the former. 

 But from whence can this enormous increase of the power come? 

 If we say that it is the character of this force, and content 

 ourselves with that as a sufficient answer, then it appears to me 

 we admit a creation of power, and that to an enormous amount ; 

 yet by a change of condition so small and simple, as to fail in 

 leading the least instructed mind to think that it can be a suffi- 

 cient cause : we should admit a result which would equal the 

 highest acts our minds can appreciate of the working of infinite 

 power upon matter ; we should let loose the highest law in 

 physical science which our faculties permit us to perceive, 

 namely, the conservation of force. Suppose the two particles 

 A and B removed back to the greater distance of 10, then the 

 force of attraction would be only a hundredth part of that they 

 previously possessed ; this, according to the statement that the 

 force varies inversely as the square of the distance, would double 

 the strangeness of the above results ; it would be an annihilation 

 of force ; an effect equal in its infinity and its consequences 

 with creation, and only within the power of Him who has cre- 

 ated. 



We have a right to view gravitation under every form that 

 either its definition or its effects can suggest to the mind ; it is 

 our privilege to do so with every force in nature ; and it is only 

 by so doing, that we have succeeded, to a large extent, in re- 

 lating the various forms of power, so as to derive one from 

 another, and thereby obtain confirmatory evidence of the great 

 principle of the conservation of force. Then let us consider 



