228 COSMICAL ARRANGEMENTS. 



an emanation ; and all emanations are inversely 

 as the square of the distance, as light, odours. To 

 this Clairault replies by asking how we know that 

 light and odours have their intensity inversely as 

 the square of the distance from their origin : not, 

 he observes, by measuring the intensity, but by 

 supposing these effects to be material emanations. 

 But who, he asks, supposes gravity to be a mate- 

 rial emanation from the attracting body. 



BurFon again pleads that so many facts prove 

 the law of the inverse square, that a single one, 

 which occurs to interfere with this agreement, 

 must be in some manner capable of being ex- 

 plained away. Clairault replies, that the facts do 

 not prove this law to obtain exactly ; that small 

 effects, of the same order as the one under dis- 

 cussion, have been neglected in the supposed 

 proof; and that therefore the law is only known 

 to be true, as far as such an approximation goes, 

 and no farther. 



Buffon then argues, that there can be no such 

 additional fraction of the force, following a dif- 

 ferent law, as Clairault supposes : for what, he 

 asks, is there to determine the magnitude of the 

 fraction to one amount rather than another? 

 why should nature select for it any particular 

 magnitude ? To this it is replied, that, whether 

 we can explain the fact or not, nature does select 

 certain magnitudes in preference to others : that 

 where we ascertain she does this, we are not to 



