Water and the Plant 89 
51. Pour gently and slowly a pint of water into the top of each 
chimney. The water that drips through is free water; that which 
is kept has become capillary water. Compare as to time when 
water begins to drip, length of time the dripping continues, and 
amount of water retained. 
How does the addition of humus affect the water-holding 
power of sandy soils? How does sand improve a clay soil? 
