NATURAL THEOLOGY. 19 



planets were originally masses of matter, struck 

 off in a state of fusion, from the body of the sun, 

 by the percussion of a comet, or by a shock from 

 some other cause, with which we are not acquaint- 

 ed : for, if these masses, partaking of the nature 

 and substance of the sun's body, have in process 

 of time lost their heat, that body itself, in time 

 likewise, no matter in how^ much longer time, must 

 lose its heat also, and therefore be incapable of an 

 eternal duration in the state in which we see it, 

 either for the time to come, or the time past. 



The preference of the present to any other 

 mode of distributing luminous and opaque bodies, 

 I take to be evident. It requires more astronomy 

 than I am able to lay before the reader to show, 

 in its particulars, w^hat would be the effect to the 

 system, of a dark body at the centre and one of 

 the planets being luminous : but I think it manifest, 

 without either plates or calculation, first, that sup- 

 posing the necessary proportion of magnitude be- 

 tween the central and the revolving bodies to be 

 preserved, the ignited planet would not be suffi- 

 cient to illuminate and warm the rest of the sys- 

 tem ; secondly, that its light and heat would be im- 

 parted to the other planets much more irregularly 



