EXPERIMENTS AND PRACTICAL WORK 63 



constituents together in the proper proportions, make 

 different types of soil. Label and put away 



(a) A sandy soil. 



(b) A loam. 



(c) A clayey soil. 



(d) A marl. 



MORE ABOUT THE SOIL 



(See Tropical Readers, Book II, pp. 87 and 88.) 



Expt. 108. Available Plant Food. liepeat Experi- 

 ment 77, showing that the soil has plant food in 

 solution. 



Expt. 109. The Finer the Tube the Higher the 

 Liquid rises. Put two glass tubes of different bore 

 in a vessel of water coloured with red ink. Note that 

 the water rises higher in the smaller tube. 



Expt. 110. Rise of Water through Porous Sub- 

 stances. Put the end of a piece of chalk into some 

 ink, and note the rise of the ink; show similar action 

 with three other substances, e.g. blotting paper. 



Expt. 111. Rise of Water through Soil. 



(a) Put some soil into a glass tube or into a lamp 

 chimney; tie a piece of cloth over the bottom and put 

 it to stand in a vessel containing about 1 in. of water. 

 Examine after some hours, and notice that the water 

 has worked its way up through the soil, which has 

 become moist some distance above the level of the 

 water. 



(b) Make a drawing representing a section of soil, 

 and showing surface soil, impervious strata, and water 

 level; draw a kerosene lamp, lighted, and make notes 

 showing the similarity of evaporation of water from the 

 surface of the soil to loss of oil from a burning wick. 



