96 THE NATURE STUDY COURSE. 



leaves, etc , make the close clay mellower and more pervious 

 to circulation of air. 



A different way of teaching a classification of soils is to 

 have the pupils bring samples — one or more, or as many 

 different kinds as they can find — from their homes. These 

 may be brought in tin cans or strawberry boxes, or even paper 

 bags. Collectors should be charged to note carefully or 

 remember where each specimen was taken from and its depth 

 from the surface. Each one may be emptied out on a board 

 or slate and examined by the class as to texture, composition, 

 color, and other qualities, and broadly referred to its class. 

 By the time that a dozen or more unlike samples have been 

 studied the pupils will have acquired considerable knowledge 

 of soils and skill in classifying them. Typical specimens may 

 be set aside in gem jars or boxes and labelled. 



Water Capacity of Soils. — It may have been observed that 

 a certain flowerpot dries out much more quickly than another 

 of the same size. Why is this the case ? The pupils may offer 

 two reasons — (1) the plant in the first uses more water, ('2) 

 the soil in the second retains water longer. Let us experiment 

 to find out whether some soils have more power to retain 

 moisture than others. To-morrow bring samples of different 

 kinds of soil in tin fruit-cans. Inquire who can bring clay 

 loam ; who, gravelly soil ; who, leaf-mould, etc. Before you 

 fill the can make four nail-holes in the bottom of it. 

 We shall need to weigh the samples. Who will bring a spring 

 balance ? (Trustees will become willing to procure weighing 

 appliances for the school when they hear how much you need 

 them.) 



The samples are brought, saturated with water and weighed 

 after the water ceases dropping from them. They are weighed 

 on each of several subsequent days and the percentage of loss 



