HOW PLANTS FEED. 247 



will do this by root action, by capillary attraction, by osmose 

 diffusion. I don't care by what name you call it, by some 

 tremendous enetgy this water is thrown to the leaf, and there 

 Nature boils it down. About ninety-five per cent of all the 

 water which goes up from the root is thrown out of the leaf 

 into the air ; about five per cent remains in the leaf for the 

 use of the plant. And in this wonderful leaf of which I have 

 spoken now we find this union takes place : the five per cent 

 of water and carbonic acid taken from the air unite, and by 

 the most delicate, the most wonderful, the most mysterious 

 processes, within the plant. With these two substances, 

 water, and the carbon which has been taken out by the 

 decomposition of carbonic acid, this plant will make all 

 the organic substances, will make all the aroma of all your 

 fruits and your flowers, wi]l make all the gum, and all the 

 starch, and all the sugar, and all the woody fibre which build 

 up and make the great mass of the structure of your plants ; 

 and along with it, as it is deposited to build up the structure 

 by the boiling-down process I have spoken of, or the reduc- 

 tion by throwing off the water. Nature will have deposited 

 a little bit, the slightest possible quantity, of material taken 

 out of the soil, and which it has carried and deposited in the 

 plant which we find, and call " ash." 



Now, then, this plant, so far as we know, has fed on two 

 things, and only two, — the gas taken from the air by the 

 leaf, and the water, which was the weakest possible solution, 

 taken from the soil. There is nothing else the plant could 

 take by either of these sets of organs ; and the structure must 

 be built up and composed of the material taken from the soil 

 and the water by these organs in the forms I have mentioned. 

 Now, then, if the plant did not find in the soil nor in the air 

 the material necessary to build up its structure, and find it 

 in the way here indicated (in the form of gas in the air, and 

 the form of solution in the soil), the plant could not grow; 

 and the distinctive difference between a soil fertile and a soil 

 sterile is not that there is no lime in the soil, is not that there 

 is no potash in the soil, because you might plant a potato- 

 plant, which is a potash-plant, where it should send its root- 

 lets down into felspathic sand, and it would die for tlie want of 

 potash ; or you might plant a wheat-plant on the soils of the 

 Charleston basin, where it might send its rootlets directly 



