THE LEAF 91 



root, dandelion, violets, lettuce, hyacinth, and in trees 

 such as the apple, pear, oak, etc. 



Plants and the Atmosphere. 



Put about an ounce of slaked lime (building lime) into 

 a wine-bottle full of water ; shake well and allow to settle. 

 The clear liquid is lime-water, and should be carefully 

 poured off and kept ready for use 

 in another bottle. 



Take a dry wide-mouthed "T^" M 



bottle, such as a jam-bottle ; pour -** ' ^ 

 into it a little lime-water and shake 

 gently. The lime-water remains 



J 



clear, showing that in ordinary air 





very little, if any, carbon dioxide 

 is present. 



Fasten a small piece of char- 

 coal to a thin wire, ignite the 

 charcoal, and, using the wire FIG. 10. Charcoal burning 

 as a handle, hold it in a dry in glass jar. 



wide-mouthed bottle similar to that used in the pre- 

 vious experiment (see Fig. 10). It is well to pass the 

 wire through a cork or piece of cardboard, so as to close 

 the mouth of the bottle while the burning charcoal is in 

 it. After the charcoal has been burning for a few minutes 

 the flame will go out, all the oxygen in the bottle having 

 been used up. Remove it, pour in some lime-water, and 

 shake gently : the lime-water will become cloudy owing 

 to the formation of carbonate of lime (chalk) by the union 

 of the lime with the carbon dioxide produced by the char- 

 coal burning in the oxygen of the air. 



