THE ECONOMY OF NATURE. 493 



following potato, &c. But, above all, agriculturists learned 

 that in the long-run there is nothing so cheap as manure, i.e. 

 the return to the soil by animals of the elements which these 

 animals took out of it. 



On the right hand of the illustration (page 495) is shown the 

 simplest mode of enriching the soil, namely, by spreading the 

 manure on the surface of the earth, and then digging it in. 

 Any mode of thus enriching the earth is a proof of civilisa- 

 tion. No savage ever dreamed of such a thing, and I doubt 

 whether barbarians recognised the principle at any time. 



Nowadays we have recognised the necessity of returning to the 

 soil in one form the elements which we have taken from it in 

 another. As usual in such arts of civilisation, the Chinese 

 have long preceded us. They waste nothing, carrying, perhaps, 

 its principles to an extent which scarcely suits our European 

 ideas. 



They even utilise the little clippings of hair, to which every 

 Chinaman is almost daily subject, if he wishes to keep up his 

 self-respect in public. The barbers carefully preserve these 

 clippings, and sell them to gardeners. They are too precious 

 to be used in general agriculture, but the flower artist, when 

 he plants the seed, puts in the same hole a little pinch of human 

 hair, knowing it to be a strong stimulant to growth. 



WITHOUT multiplying examples of artificial manuring, most 

 of which are too familiar to need description, we will proceed 

 to the methods by which Nature has for countless centuries 

 achieved the same work that Man has lately learned to under- 

 take. 



Nature abhors waste, and in the long-run will prove it, 

 however wasteful may be the ways of her servants. Take, for 

 example, the case of an ordinary tree, such as an elm, an oak, 

 or a birch. In the autumn the leaves fall. In the next 

 summer scarcely a dead leaf can be found. They have been 

 decomposed by rain, dews, and gases, and have thus returned 

 to the earth more than the nutriment which they took out 

 of it. 



Here man is apt to interfere. Knowing the invaluable produc- 

 tive powers of decayed leaves, he removes them as they fall, and 

 stores them in heaps so as to form the costly, but almost incus- 



