44 FIELD, FOREST AND FARM 



"A leaf is riddled with an infinite number of ex- 

 cessively minute orifices, each encircled by two lips 

 which give it the appearance of a half -open mouth. 

 They are called stomata. On a single leaf of the 

 linden more than a million can be counted, but so 

 small are they as to be quite invisible without a mag- 

 nifying-glass. This picture shows you how they 

 look under a microscope. Well, through these ori- 

 fices the plant breathes, not pure air such as we 

 breathe, but poisoned air, fatal to an animal but 

 wholesome for a plant. It inhales through its myri- 

 ads of millions of stomata 

 the carbonic acid gas dif- 

 fused through the atmos- 

 phere; it admits this gas into 

 the inner substance of its 

 leaves, and there, under the 

 sun's rays, a marvelous 

 process follows. Stimu- 

 lated by the light, the leaves 

 operate upon the deadly gas 

 and take from it all its car- 



Stomata on a Linden Leaf 



bon. They unburn (the 

 word is not in the dictionary, more's the pity, for it 

 gives the right idea) — they unburn the burnt car- 

 bon, undo what combustion had done, separate the 

 carbon from the air with which it is bound up ; in a 

 word, they decompose the carbonic acid gas. 



"And do not think it any easy thing to unburn a 

 burnt substance, to restore to their original condition 

 two substances united by fire. Scientists would need 



