CONNEXION BETWEEN BLUE AND SHADE. 45 



surface, it will be found that a ring of white light occupies the 

 position of the dark circle exhibited in diagram No. 2, the 

 yellow having changed place with the blue, and now forming 

 the interior circle, whilst the red and blue appear in refractive 

 succession to the ring of white light. 



From this it is evident that there is a connexion between the 

 Hue and shade when in a state of refraction, and that it seems to 

 exercise a power of operation by which the appropriate polarity 

 of a given portion of the compound molecules of light are 

 transmitted, in a state of privation of that luminous appearance 

 which they would otherwise exhibit, if not interfered with by 

 the hydrogenating influence of the blue ray in its abstracted 

 capacity. 



It is equally e vident that to the yellow ray similarly refracted, 

 and occupying the interior circle of the annular spectrum, as 

 described by reference to Diagram No. 3, Plate I., this yellow 

 circle exercises a similar affinity or power of connexion with a 

 band of white light, which accompanies it in the same rotation, 

 and occupying the same area and space, as the black or dark 

 shade is found to do, while accompanying the blue circle, as 

 shewn by Diagram No. 2, Plate I. The comparative intensity 

 of the illuminating powers of the several portions of the spec- 

 trum are in direct accordance with these phenomena, as the 

 higher illuminating power has always been attributed to the 

 light orange homogeneous yellow and light green ; while the 

 blue, purple, and violet are comparatively deficient of such ad- 

 mirable splendor. 



It will therefore appear that the interferences of the blue ray 

 in its abstracted state of refraction, is calculated to obstruct per- 

 fect light by the interposition of shade; while, on the contrary, 

 the yellow ray possesses the power of promoting the effulgence 

 of light by preserving, by its influence, an adjunct band of white 

 light, retained in its regular order of polarity, in other words, 

 in an imrefracted state. 



