. Agriculture for beginners. urishment from two sources,—fromthe air and from the soil. The soil food, or mineral food,must, dissolved in water, reach the plant through the roothairs, with which all plants are provided in great of these hairs may be comparedto a finger reaching among the par-ticles of earth for food and we examine the root hairs ever soclosely, we find no holes, or openings,in them. It is evident that no solidparticles can enter the root food must then pass into theroot in solution. An experiment just here will helpus to understand how a root fe
. Agriculture for beginners. urishment from two sources,—fromthe air and from the soil. The soil food, or mineral food,must, dissolved in water, reach the plant through the roothairs, with which all plants are provided in great of these hairs may be comparedto a finger reaching among the par-ticles of earth for food and we examine the root hairs ever soclosely, we find no holes, or openings,in them. It is evident that no solidparticles can enter the root food must then pass into theroot in solution. An experiment just here will helpus to understand how a root a narrow glass tube like theone in Fig. 22. If you cannot geta tube, a narrow, straight lamp chim-ney will, with a little care, do nearlyas well. Cut from a bladder made soft by soaking, a piecelarge enough to cover the end of the tube or chimney andto hang over a little all around. Make the piece of blad-der secure to the end of the tube by wrapping tightlywith a waxed thread, as at B. Partly fill the tube with. Fig. 22. ExperimentTO SHOW HOW RootsTAKE UP Food 32 AGRICULTURE FOR BEGINNERS molasses (or it may be easier in case you use a narrow tubeto fill it before attaching the bladder). Put the tube intoa jar or bottle of water so placed that the level of themolasses inside and the water outside will be the the tube in this position, and observe it frequentlyfor three or four hours. At the end of the time you shouldfind that the molasses in the tube has risen above the levelof the liquid outside. It may even overflow at the top. Ifyou use the lamp chimney, the rise will not be so clearlyseen, since a greater volume is required to fill the space inthe chimney. This increase in the contents of the tube isdue to the entrance of water from the outside. The waterhas passed through the thin bladder, or membrane, and hascome to occupy space in the tube. There is also a passagethe other way, but the molasses can pass through the bladdermembrane so slowly that
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