332 THE CHEMISTRY OF CREATION. 



these matters at once, and the air is all the 

 clearer afterwards. 



It will be necessary, in a future page, to 

 advert to the use of the Trade Winds in carrying 

 forward and preserving the purity of the at- 

 mosphere on the whole. They also subserve 

 another and scarcely less important function 

 that of preserving in a sort of equilibrium the 

 temperature of the atmosphere, and to some 

 extent of the regions over which their influence 

 is felt. The tropics are thus the perpetual 

 sources of enormous floods of warm air, which, 

 rising up and flowing over, proceed ultimately 

 to the poles, and in all probability exert a very 

 considerable modifying influence over the seve- 

 rity of the arctic regions, as well as over those 

 which they traverse on their way thither. 



How wonderful is the unity and dependence 

 of creation ! The movement even of a breath 

 of air is not without its purpose and its end. 

 Let this soft and scarcely sensible current, 

 which as we talk of these things here salutes 

 our cheek, when we are reminded of all the 

 marvels of its origin, and of the intentions for 

 which it has been put in motion, waft our 

 praises to Him whose divine power and love 

 reveals itself even in a summer wind ! 



