40 



PRACTICE 19 



Effect of Organic Matter on Retention of Water 



Use same tubes as in preceding practices but compact in one, 

 sand, and in the others sand and peat in the following proportions: 

 95 grams of sand and 5 grams of peat thoroughly mixed, 90 grams of 

 sand and 10 grams of peat, 80 grams of sand and 20 grams of peat and 

 60 grams of sand and 40 grams of peat. 



Treat as in the preceding and determine the grams of water re- 

 tained, also the percent of water retained based upon the total 

 amount of sand and peat used in each tube. 



How many grams of water did the 5 grams of organic matter re- 

 tain? The 10 grams? The 20 grams? The 40 grams? 



