AGRICULTUEE ON CLIMATE. 187 



extended over many hundreds or even thousands of years, 

 while the productiveness of the soil has perhaps increased ; 

 notably in England, China and Japan. Islands are less de- 

 pendent for their rain-fall on the evaporation from their 

 own area than are continents. The British Islands espe- 

 cially owe their moist climate to the warm waters of the 

 Gulf Stream by which they arc partially surrounded. Nor 

 is England an exporter of agricultural products, but, on the 

 contrary, an immense importer, and not only of food, but, of 

 raw material for her manufactories, and a large portion of the 

 waste from these goes to sustain her soil. She is also a 

 large importer of fertilizers direct, most of the Pacific guano 

 having gone to her shores. 



From China and Japan rice, the only article of food ex- 

 ported, is largely the product of low lands, partially de- 

 pendent for fertility on inundations. This is also the prin- 

 cipal food of the inhabitants. The condition of both these 

 countries is somewhat analogous to that of some farms bor- 

 dering on the marshes of our sea-coast, the owners of which 

 are enabled to sell oif the product of their upland, keeping 

 up its fertility by the manure resulting from a liberal feeding 

 of marsh hay to cattle. 



The Japanese practise irrigation to a considerable extent. 

 They also testify their appreciation of the importance of 

 trees by laws which require the setting out of two for each 

 one destroyed. It is said that, considering the large popula- 

 tion on so small an area, the number of trees in Japan is 

 astonishing. 



To place the whole matter in proper light, we have only 

 to ask the question. Had China and Japan been dependent 

 on the product of their uplands for food for man and beast, 

 and had they exported a large portion of all their agricultu- 

 ral products, and had they also practised our modern system 

 of city sewage, at the expiration of 3,000 years would they 

 have contained, as they now do, more than 500,000,000 of 

 inhabitants, nearly one-half the total population of the globe, 

 and their soil still furnishing an abundance of food for all ? 



Good reasons may perhaps be given for a law taxing cer- 

 tain kinds of imports, but it is by no means certain that a tax 

 on some exports would not be the wiser enactment ; nor is 



