70 'HIE YLAll. 



depending upon the same general causes, takes the 

 same direction, unless where that is modified by the 

 action of different surfaces. Now, the ice which ac- 

 cumulates in the polar seas during the winter is super- 

 ficially lighter than the water, and accordingly floats 

 above it: when it is forming, therefore, it does not 

 occasion a current from the regions of the pole, but 

 rather a current to them, of warmer water of course 

 than that which is there before. But when the ice 

 melts, and the snow upon the polar lands and fields 

 and bergs of ice at the same time, a surplus of water is 

 produced ; and there is a tendency toward the equator, 

 at the same time that there is in the regions of the 

 equator a tendency toward the pole. Thus the form 

 of the earth, and the way in which its motions expose 

 different surfaces of it to the action of the sun, give to 

 the great mass of waters a constant tendency to the 

 place where the action of the sun is most intense ; and 

 the very ice which the winter collects in the chilling 

 regions, is an annual store of drink laid up for the 

 plants and the animals of regions which are warmer, 

 and which, but for some such action as this, would be 

 tenantless and bare. In this we see how beautifully 

 the system of nature works, and how one single prin- 

 ciple, which we are very apt to pass unheeded, can 

 produce results that to us are innumerable, and which, 

 the more we contemplate them, shew up to us the wider 

 a field of utility and of gratification. And it is in this 

 greater philosophy that the chief value of the study of 

 nature consists, and not in the consideration of those 

 objects that address themselves singly to the senses, 

 however beautiful they may be in their forms, or how- 



