PHipps] SOIL EXPERIMENT 155 



ing about an eighth of an inch square, the next about a sixteenth 

 of an inch, and the third small enough to catch the medium sized 

 sand. The gravel is caught in the first sieve, the coarse sand 

 m the second, and medium sized sand in the third. That which 

 passes through the final sieve may be called a mixture of fine 

 sand, clay and silt. Each of these ingredients should be weighed 

 and noted. 



Separate the fine sand from the clay and silt by pouring 

 water upon the mixture in a beaker or tumbler, stirring, and 

 quickly but carefully pouring off into another dish the muddy 

 water. Dry and weigh the fine sand left, and estimate the 

 amount of clay and silt. This latter may be regained by evap- 

 orating the muddy water. 



More interesting and helpful data may be obtained by find- 

 ing the volume of the soil by means of a rectangular measure 

 having a cross-section area of one square inch. The amount 

 of water contained in one cubic inch of the soil may then be 

 known, and the amount in a cubic foot estimated. 



A permanent exhibit of the results of the experiment may 

 be kept by placing samples, or actual amounts, of each constitu- 

 ent found in the soil analyzed, in small flat bottles and mount- 

 ing on a large cardboard with suitable labels and explanations. 

 The percentage of each material found may easily be worked 

 out by the class, and the diflFerent weights added to see if the 

 original 100 grams have all been accounted for. 



The experiment may be repeated, using other soils taken 

 from the home garden, the field, and other places, and a com- 

 parison of results made. If samples of the constituents found 

 are placed in pots, and seeds, flowers or weeds planted in them 

 and watched by the children from day to day, a lesson is taught 

 concerning the necessity of water, organic material and other 

 substances in the soil for growth of plant life. A record of the 

 experiment with all data should be kept by the pupils, written 

 carefully in notebooks, the training in accurate written expression 

 proving most helpful. 



This simple analysis does not of course take into account 

 some chemical constituents of the soil so necessary to the growth 

 of plants, but it serves several important ends, especially if the 

 experiment is done by the pupils. Useful training in weighing 

 is given, opportunity is afforded for developing the powers of 

 observation and inference, and a much better knowledge of what 

 soil is and its relation to plant growth is impressed upon the 

 child's mind. This experiment may well be followed by other 



