54 THE CHEMISTRY OF CREATION. 



and the contrary with respect to the blade of 

 grass. 



But more than this : while every flower that 

 blows is dependent upon heat for its expansion, 

 and the perfection of its various functions, 

 flowers differ from one another in what we may 

 call the amount of their debt. Some absorb 

 much heat, and with great rapidity ; others 

 absorb less, and that slowly. Strange to say, 

 this is connected with their various colours, 

 for it has been proved by philosophical experi- 

 ments that bodies variously coloured have dif- 

 ferent absorbing and radiating powers with 

 respect to heat.- Dr. Franklin placed pieces of 

 cloth of different colours in the sunshine on the 

 surface of snow in winter, and found that in 

 proportion to the depth of the colour, the snow 

 melted most rapidly, in consequence of the deep- 

 coloured pieces having absorbed heat much 

 faster than the rest. When we look therefore 

 at the flower-garden all begemmed with brilliant 

 colours, how interesting is it to remember these 

 colours were not given in vain. The streaked 

 tulip and the spotless garden lily do not absorb 

 or radiate heat alike. The deep blush of the 

 rose, the pale azure of the blue-bell, the glow- 

 ing gold of the meadow butter-cup, are not 

 therefore merely ornaments, or intended only 

 to give variety to the scene, though doubtless 



