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projecting ornaments, the eye would be 

 harassed and distracted, and there would 

 be a want of repose ; on the other hand, 

 if the whole were smooth and even, there 

 would be a want of spirit and animation. 



It may be objected to this notion of the 

 effects of smoothness and roughness, that 

 the most highly polished, and consequently 

 the smoothest of all surfaces, are those 

 which most strongly reflect the light, and 

 of course most powerfully irritate the 

 organ. But here likewise roughness, in 

 which term , I mean to include whatever is 

 sharp, pointed, angular, or in any way 

 contrary, to smoothness, produces the effect 

 I have ascribed to it : for when smooth 

 polished surfaces are cut into sharp angles, 

 the irritation is infinitely increased, A 

 table diamond, for instance, like other 

 highly polished objects, has a considerable 

 degree of stimulus ; but it is only when 

 cut into a number of sharp points and 

 angles, that it acquires the distinguished 

 title of a brilliant. Light itself, when bro- 

 ken in its passage, though the quantity be 



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