206 BOOK OF NATURE LAID OPEN. 



There is one thing to be remarked with regard to 

 the tails of comets, that they appear always in a di- 

 rection averted from, or contrary to, the sun ; and 

 this certainly, with the circumstance of the stars be- 

 ing visible through them, gives colouring to the sup- 

 position that they are nothing more than merely a 

 condensation of the solar rays, by the refracting 

 power of the comet and its atmosphere. 



With regard to the purposes for which comets 

 were created, <* all is doubt, uncertainty, and con- 

 jecture." Some have supposed they are the means, 

 appointed by the Almighty, for putting a period to 

 the planetary world; others have imagined that co- 

 mets, in their several revolutions, gradually approach 

 the sun, till at last they fall into it, and become a sup- 

 ply of fuel to that luminary; and some of the learned 

 world, Dr. Mavor remarks, are of opinion, that they 

 are places of future punishment for tormenting the 

 damned with eternal vicissitudes of heat and cold; 

 " but when, on the other hand," as the Doctor goes 

 on, " we reflect on the infinite power and goodness 

 of the Deity, the latter inclining, the former enabling 

 him to make creatures suited to all states and circum- 

 stances; that matter exists only for the sake of intel- 

 ligent beings; and that, wherever we find it, we al- 

 ways perceive it pregnant with life, or subservient 

 to that purpose ; when we consider the numberless 

 species, the astonishing diversity of animals, in earth, 

 air, water, and even on other animals ; every blade of 

 grass, every tender leaf, every natural fluid, swarm- 

 ing with life, and every one of these enjoying such 



