64 



oilier different degrees of thickness, -or thinness of the 

 prominent little parts of the surfaces of bodies. Light 

 acts upon bodies by heating, dissolving, and putting 

 their parts into a vibrating motion. Bodies act upon 

 light, in drawing its parts to them, and that m lines 

 perpendicular to their surfaces. And as there may be 

 different degree* of attraction in bodies, which produce 

 their different degrees of elasticity and cohesion, so 

 there must be' different degrees of attractions in mediums 

 supposed, to account for their different powers, in 

 bringing the refracted rays nearer to, or farther from 

 the perpendicular. For it is well known all mediums 

 have not the same refractive virtue. Now what a 

 beautiful, uniform, and simple theory of light is here I 

 This is so very like the frugal simplicity, and yet the 

 manifold variety of nature, that one would be almost 

 tempted to believe it true, were there no experiment to- 

 confirm it. We may observe one more instance of the 

 wonderful wisdom of nature, in the propagation of 

 light,' viz. That a ray of light in passing from a luminous 

 point, through two differently refracting mediums, to 

 illuminate a given point, spends the least time (the re- 

 fracting powers of the several mediums considered) 

 possible; and consequently when a ray passes through 

 one medium, from a luminous point to reflect upon a 

 given point, it takes the shortest way possible. This 

 the geometers have demonstrated. Now is not this an 

 instance of counsel and design? Is not this like the 

 methods of wisdom, which will not spend more time on 

 a thing than just what is necessary to do the business; 

 which will not go about, but take the shortest course 

 possible that 'will bring it to the place designed T 



The islands of Sciily have been so noted among the 

 ancients, one might expect to rind among the inhabitants 

 somt consciousness of their own antiquity, "and of their 

 appearance in history before the other parts of Britain 

 were at all known. But there is nothing of this kind ; 

 the inhabitants are all newcomers, not an old habitation 

 worth notice, jaor any remains of Phoenician; Grecian^ 



