*COtO&IFlCATION IN GENERAL. 329 



With respect to vision, a body, 

 such as this, would be a perfect blank, 

 invisible to the eye, and only cognisable by 

 the resistance which it gave to the sense of 

 touch. 



The same consequences would ensue with 

 respect to what is called WHITE. If a body 

 appear to be white, because it reflects all the 

 rays, and absorbs none of them; it is impos- 

 sible that any knowledge could ever be obtain- 

 ed of a white body by the eye ; since, in such a 

 TOse, it must be destitute of color altogether. 

 I would, however, ask whether there be any 

 solid ground for supposing that the different 

 impressions made on our organs of vision by 

 the particular rays which flow from particular 

 bodies, are not equally referable to them all, with- 

 out any exception. I would ask whether any 

 exception ought to be made with respect to jet 

 'and to snow? Whether the rays which flow from 

 both, by which the impressions on our optic 

 sense excite the sensations of white and black, 

 have not an actual existence within those bodies, 

 or at least on their external surfaces, as much 

 as on those of gold or indigo ? Whether the white 

 wax and the black wick of which my candle is 

 composed, are not as obvious to the eye, and 

 as referable to the same cause, as the red flame 

 that issues from it ? I would ask whether that 

 hypothesis be built upon a legitimate assurop- 



