246 BOARD OF AGRICULTURE. 



thing, but what is in the form of a gas ; and thus, as we all 

 know, carbonic-acid gas, and perhaps carbonate of ammonia, 

 taken through the leaf, is the food which the leaf gathers for 

 the building-up of the plant, and which was the ninety-eight 

 per cent of the weight of the oak-wood which disappeared 

 when we burned it in the fire. Ninety-eight per cent, then, 

 of the weight of the oak, to speak in general terms, was 

 gathered by the leaf out of the air in the form of gas, and 

 the leaf had capacity to gather and take in nothing else. 

 Nearly all the food of the plant, then, when taken up is 

 simply gas. 



Going now to the roots, the other feeding-organs, we find 

 here a very wonderful development. First are the trunk- 

 roots, — large, strong, similar in many respects to the trunk 

 of tlie tree or the shrub itself; but, branching out in all direc- 

 tions in the soil, they become smaller and smaller, attenuated 

 until they become simply a mass of fibrous, thread-like root- 

 lets, following the surface of the soil for a long distance 

 around every plant, and to very great depths ; permeating, 

 winding their way through, all its interspaces, apparently 

 clinging to the small stones within the soil, and by their 

 numberless root-hairs taking into and clasping in their em- 

 brace all the finer particles of soil. And what are these 

 roots doing? What are they made for? What is their 

 capacity to gather food, if they are feeding-organs of the 

 plant? Examine them under the microscope, and tell me 

 what their work is, and how they perform it. Why, so far 

 as we know, these millions of little rootlets that feed the 

 plant are doing nothing but gathering water out of the soil : 

 that is all they can do. There is nothing in the soil that 

 they can do any thing with but water : it is all that they can 

 gather. 



Now, then, is it pure water that the roots gather? Noth- 

 ing ever entered their portals but in the fi»>rm of water. Per- 

 haps it is a solution. Let us take the water that the roots 

 gather from the soil, and see what it is. Apply your chem- 

 ical tests to it, and it comes so near being pure wate^', that 

 the most delicate tests can detect nothing, unless it is the 

 most obscure trace of any thing, but water; and, if there is 

 any thing there, we must boil it down before we can deter- 

 mine with certainty what it is. Let it alone, and the plant 



