PROBLEM 59 



77 



Problem 58 : To test organic material in soil. 



Materials. — Samples of different kinds of soUs, balance and 

 weights, Bunsen burner, pieces of tin. 



Method. — Obtain a small quantity of vegetable mold, rich gar- 

 den soil, and soil from a sandy road. Allow each lot to remain for 

 several days in a dry place so as to remove surplus water. Then 

 take eight ounces of vegetable mold from a forest, eight ounces of 

 rich soU from a garden, and the same amount from a sandy road. 

 Weigh carefully, place each on a piece of tin or sheet iron, and heat 

 red-hot for at least 20 minutes. Now reweigh each sample. 



Observations. — Tabulate results as follows : 



Conclusion. — 1. How do you account for the losses in weight? 

 2. Might there be a loss of more than one substance to account 

 for this? 



Problem 59 : To find what kind of soil holds water best. 



Materials. — Gravel, sand, clay, loam, leaf mold, wide-mouth 

 bottles, balance and weights, one-hole rubber stoppers, glass 

 tubing. 



Method. — Weigh out an equal amount of gravel, sand, clay, 

 rich loam, leaf mold, and one quarter as much by weight of dry 

 leaves. Prepare six bottles, cut out the bottoms, placing the 

 various materials in the bottles as shown in the lower figxire, page 

 78, Civic Biology. Into each bottle now pour slowly one pint 

 of water. 



Measiure the amount of water that drips through each bottle. 



