LE TERRIER AND ADAMS* PLANET. 



urinating and heating pojver of the sun are based upon the supposi- 

 tion that his light is received under like physical conditions ; and 

 that many conceivable modifications in the physical state of the 

 body or medium on or into which the light falls, and in the 

 structure of the visual organs which it affects, may render light 

 of an extremely feeble intensity as efficient as much stronger light 

 is found to be under other conditions. 



26. Messrs. Lassell and Challis have at times imagined that 

 indications of some such appendage as a ring, seen nearly edge- 

 wise, were perceptible upon the disc of Neptune. These conjec- 

 tures have not yet received any confirmation. When the 

 declination of the planet shall have so far increased as to present 

 the ring, if such an appendage be really attached to the planet, at 

 a less oblique angle to the visual ray, the question will probably 

 be decided. 



102 



