NATURAL THEOLOGY. 11 



converts a tremendous element into a welcome 

 visiter. 



It has been observed to me by a learned friend, 

 as haviniv often struck his mind, that, if light had 

 been made by a common artist, it would have 

 been of one uniform colour : whereas by its pre- 

 sent composition, we have that variety of colours 

 which is of such infinite use to us for the distin- 

 guishing of objects ; which adds so much to the 

 beauty of the earth, and augments the stock of our 

 innocent pleasures. 



With which may be joined another reflection, 

 viz. — that, considering light as compounded of 

 rays of seven different colours (of which there can 

 be no doubt, because it can be resolved into these 

 rays by simply passing it through a prism,) the 

 constituent part must be well mixed and blended 

 together, to produce a fluid so clear and colour- 

 less, as a beam of light is, when received from 

 the sun.'' 



'* The substitution of the undulatory for the atomic theory of 

 Hght would produce no alteration whatever in the author's con- 

 clusions ; and, so far from diminishing, would rather increase 

 the astonishment which the phenomena of Optics are calculated 

 to excite. The same may be said of the discoveries made partly 

 since Dr. Paley's time, partly immediately before the composition 

 of his work, of the two other kinds of rays which accompany 

 those of light ; the calorific, or heat-making, which partly mix 

 with the colorific, or colour-making, of the spectrum, and partly 

 fall beyond the least refrangible rays ; and the chemical, which 

 affect certain metalic salts, without either producing illumination 

 or exciting heat, and which are to be found among and beyond 



