232 IRRIGATION. 



that gas. Give the geine this oxygen, condensed in water: 

 wet it with this concentrated oxygen, crowd it into geine, as 

 would be done by overflowing a meadow with water. It 

 penetrates every crack and cranny, and every mole's-eye 

 hole ; it expels the carbonic acid imprisoned under the sod. 

 It is doing the same work upon the untouched green sward, 

 which would be effected by ploughing and tillage. The long 

 and the short of the whole action of irrigation with pure 

 limpid water is, that its absorbed oxygen converts insoluble 

 to soluble geine. Is this explanation which science offers, 

 confirmed by practice*? The appeal is made to all "who 

 have attended either to the theory or practice of irrigation, 

 to bear witness to its truth. Is it not admitted that the run- 

 ning waters are alone fit for this purpose ? That after re- 

 maining a few days they are abated, and a new^ flood must 

 cover the land ? Is not this necessity of renewing at short 

 periods the covering of water which shows no deposit, a 

 proof that it has given up some invisible agent to fertilize 

 the earth ? This invisible agent is oxygen. Is it not evi- 

 dent from the extreme slowness with which air is absorbed 

 by water, that if it were not for the running water, w^hich 

 every few days replaces that which has acted, that the prac- 

 tice of irrigation with pure water could be never successful 1 



282. This is the principle, a principle which, having been 

 wholly overlooked, has led to a waste of time and money, 

 and has given to irrigation, in many minds, the odor, if not 

 of a bad, at least of a useless practice. Where, guided by 

 this light of science, grass lands can be irrigated, let it be 

 done. If the experience of the most enlightened agricultur- 

 ists in Europe is not all deception, by simple irrigation with 

 nmning water, the farmer may cut two tons of hay where he 

 toils and sweats to rake off one. 



283. But bv far the most fertile source of increased cropa 



