THE SUN IN THE CENTRE. 171 



perature. No one, probably, will contend that 

 the materials of our system are necessarily lumi- 

 nous or hot. According to the conjectures of 

 astronomers, the heat and light of the sun do 

 not reside in its mass, but in a coating which lies 

 on its surface. If such a coating were fixed 

 there by the force of universal gravitation, how 

 could we avoid having a similar coating on the 

 surface of the earth, and of all the other globes 

 of the system. If light consists in the vibrations 

 of an ether, which we have mentioned as a pro- 

 bable opinion, why has the sun alone the power 

 of exciting such vibrations? If light be the 

 emission of material particles, why does the sun 

 alone emit such particles? Similar questions 

 may be asked, with regard to heat, whatever 

 be the theory we adopt on that subject. Here 

 then we appear to find marks of contrivance. 

 The sun might become, we will suppose, the centre 

 of the motions of the planets by mere mechanical 

 causes : but what caused the centre of their 

 motions to be also the source of those vivifying 

 influences? Allowing that no interposition was 

 requisite to regulate the revolutions of the system, 

 yet observe what a peculiar arrangement in other 

 respects was necessary, in order that these revo- 

 lutions might produce days and seasons! The 

 machine will move of itself, we may grant : but 

 who constructed the machine, so that its move- 

 ments might answer the purposes of life ? How 



