356 CALORIFICATION. 



the intimacy of the combination, and the nature 

 of the color will arise out of the peculiarity iu 

 the arrangement of the particles of the matter 

 with which the union is effected. The purest 

 rays, therefore, which subsist in a most ele- 

 mentary and nil combined state, as we have seen 

 before, are destitute of fire, and of color. 



When the solar rays pass through water 

 which is pure, or that which is colored, the 

 same difference in the temperature takes place. 

 At a time when the mercury of a thermometer 

 was at 61 in the air ; two other thermometers 

 were plunged into the clear, and into the co- 

 lored fluids ; while the former in fifteen minutes 

 only, rose to 64, the latter got up to 76. 



If the quality of the base, on which the solar 

 rays fall, produces such a difference in the 

 degree of temperature, is it not, I would ask, 

 legitimate to conclude, that the cause of the 

 temperature itself which is produced, is the 

 result of the chemical union, which has taken 

 place between the one and the other ; that as 

 chemical affinity, or elective attraction, altoge- 

 ther depends on the contrariety which exists 

 in the nature of the different parts, out of which 

 compounds are formed, so the intensity of the 

 temperature which is generated, will depend 

 on the contrariety which exists between the 

 purity of the solar rays, and the quality of the 

 base, with which they have combined. 



