CALORIFICATION. 351 



planetary system, are ignious or calorific rays. 

 The lunar rays have been collected and con- 

 densed through different spectra ; although the 

 illumination, in consequence produced, was 

 more splendid and brilliant than the brightest 

 flame of the best candle, no sensible increase 

 of temperature was occasioned from them ; the 

 intense degree of cold, indeed, which frequently 

 prevails during the winter season, in different 

 countries, although illuminated by the rays of 

 the moon, decidedly prove that those rays are 

 not essentially hot. The observations which 

 have been made with respect to them, during 

 the winter season, more especially apply to the 

 solar rays at all seasons. Such is the extreme 

 state of refrigeration which every substance un^ 

 dergoes, when it is exposed to their influence, 

 at the highest points of elevation, that the most 

 common observer will be led to conclude, that 

 the solar rays are not calorific rays, nor the sun 

 itself a globe of fire. It is very true, that the solar 

 rays have been examined by Dr. HERSCHELL, 

 and by other philosophers ; these experiments 

 satisfactorily prove, that the different colorific 

 rays have different degrees of temperature; 

 they, however, prove nothing with respect to 

 the temperature of pure light ; the colorific rays 

 which were separated from the colorless, 

 manifested all the phenomena of color and 

 temperature; the colorless, on the contrary. 



