AND WHAT THET ARE MADE FOR. 91 



ever changed in form in the progress from plant to animal or from one animal to 

 another, all the food and all the substance of all animals were made by plants. 

 And this is what plants are made for. 



282. Notice also that plants furnish us not merely needful sustenance, but almost 

 every comfort and convenience. Medicine for restoring, as w^ell as food for support- 

 ing health and strength, mainly comes from plants. 



283. They furnish all the clothing of man ; — not only what is made from the 

 woolly hairs of certain seeds {cotton'), or from the woody fibres of bark (linen), and 

 what is spun from Mulberry-leaves by the grubs of certain moths (as silk), but 

 also the skin and the fur or wool of animals, owe their origin to plants, just as 

 their flesh does. 



284. They furnish utensils, tools, and building materials, in great variety ; and 

 even the materials which the mineral kingdom yields for man's service (such as iron) 

 are unavailable withou| vegetables, to supply fuel for working and shaping them. 



285. They supply all the fuel in the world; and this is one special service of that 

 vegetable matter which, in the solid form of wood, does not naturally serve for food. 

 Burned in our fire-places, one part of a plant may be used to cook the food fur- 

 nished by another part, or to protect us against cold ; or burned under a steam-boiler 

 it may grind our corn, or carry us swiftly from place to place. Even the coal dui 

 from the bowels of the earth is vegetable matter, the remains of forests and herbag^ 

 which flourished for ages before man existed, and long ago laid up for his present 

 use. We may proceed one step farther, and" explain where the heat of fuel' comes 

 from ; for even a child may undei-stand it. Plants make vegetable matter only in 

 the light, mostly in the direct light of the sun. With every particle of carbonic 

 acid that is decomposed, and vegetable matter that is made, a portion of the sun's 

 heat and light is absorbed and laid up in it. And whenever this vegetable matter 

 is decomposed, as in burning it, this heat and light (how much of each, depends upon 

 the mode of burning) are given out. 



286. So all our lighting as well as warming, which we do not receive directly 

 from the sun, we receive from plants, in which sunlight has been stored up for our 

 use. And equally so, whether we burn olive-oil or pine-oil of the present day, or 

 candles made from old peat, or coal-gas, or lard, tallow, or wax, — the latter a vege- 

 table matter which has been somewhat changed by animals. And, finally, 



287. The natural warmth of the bodies of animals comes from the food they 

 eat, and so is supplied by plants. A healthy animal, no longer growin", receives into 



