SEEDS AND SEEDLINGS 115 



or on the stove and heat it hard for three or four hours, stirring it occa- 

 sionally with a glass rod. Again cool and weigh. The loss of weight 

 represents what this time ? Stir the soil sample into two liters of water. 

 Let it stand for a minute or two until the sand settles to the bottom. Pour 

 off the water and the contained silt into a second vessel. Dry the sand 

 and weigh it. Thus a rough analysis of the soil has been made. 



23. Mix a half- tumbler of garden soil with water to the consistency of 

 thick cream. Put a bit of blue litmus paper in it and let stand, noting any 

 change in color of the paper. What does the experiment show ? 



24. Fill a student-lamp chimney or long, wide glass tube with fine, dry 

 sand, tying a cloth over one end so it cannot spill out; fill another with 

 coarse dry sand, another with dry garden soil, and another with dry pul- 

 verized clay. Set all four, cloth end down, in a pan and fasten so that 

 they will not tumble over. Now pour water into the pan. Which sort of 

 soil absorbs water most rapidly? In which does the water finally rise 

 highest ? State your conclusions. 



25. Fill three low pots of equal size with garden soil. Now pour 

 100 c.c. of water into each. Sprinkle a layer of sand a quarter of an inch 

 deep in one pot, a layer of garden soil in the other, and leave the third 

 without any added soil. Weigh all and record the weights. Let them 

 stand for twenty-four hours and weigh. Weigh again at the end of forty- 

 eight hours. Record the weights and your conclusions from the experi- 

 ment. 



