2^4 ^^' Delaval on the Cattfe of the 



quor alio appeared black, when viewed by inci- 

 dent light. 



When thefe liquors are fufficiently diluted, each 

 of them tranfmit the more refrangible rays, even 

 when they are contained in the widefl: part of the 

 prifiTiatic bottles. For, the greater thicknefles 

 of diluter coloured liquors, contain no more co- 

 loured particles, than thinner mafies, which are 

 more intenfely coloured. 



Thefe phasnomena feem to indicate, that the 

 power, by which the feveral rays of light are 

 tranfmitted through Coloured Media, is inherent 

 in the Colouring Particles themfelves, and there- 

 fore, is not confined to the furfaces of fuch media. 

 For, if the tranfmifTive force was exerted at the 

 furfaces only, thinner plates of Coloured Sub- 

 fiances would aft upon the rays, as powerfully as 

 thicker mafles. But, it appears, from experiment, 

 that, in proportion as the rays pafs through differ- 

 ent thicknefles of coloured media, they exhibit 

 colours, differing, not only in degree, but, fre- 

 quently, in fpecies alfo. 



The fun's light, by which bodies are illuminat- 

 ed, confifts of all the rays, by which a white light 

 is compounded. Thefe rays, in their entire and 

 undivided ftate, are incident upon the Opake 

 Particles of Semipellucid Subftancesi and, upon 

 the Colouring Particles of Tranfparent Coloured 

 Subflancei, whenever thofe media are expofed to 

 the light. 



When 



