SECTION X 



QUANTITATIVE METHODS OF ANALYSIS 



(i) Moisture.— Weigh from 5 to 10 grams of soil into a 

 glass or aluminum dish and dry at 100^ C. until there is no 

 further change in weight. About six to twelve hours are 

 generally sufficient. Cool in a desiccator and weigh. 

 Determine all percentages of moisture on the dry basis. 



Record data as follows: 



Weight of dish and moist soil 

 Weight of dish and dried soil 

 Loss 



(A D S — W F S) 

 Percentage of moisture = x 100 



W FS 

 A. D. S. = air-dry soil. 

 W. F. S. = water-free soil. 



(2) Ammonia (Distillation) : 



Sulphuric acid solution N/14 



Sodium hydroxid solution N/14 



Indicator, cochineal or methyl-red. 

 Magnesium oxide. 



1. Transfer the culture to be analyzed to an 800-c.c. 

 Kjeldahl or a copper flask, using about 200 c.c. of distilled 

 water. 



2. Add 5 grams of magnesium oxid and some shavings of 

 paraflSn to prevent foaming. 



3. Connect to a condenser, the lower end of which is in 

 N/14 acid, 



I4.I 



