EXPERIMENTS 263 



oven and leave it four hours for the soil to dry. Cool and weigh 

 at once so there may be as little absorption of water from the air 

 as possible. From the loss of weight, calculate the per cent, of 

 hydroscopic moisture in the soil. (Soils from the students' home 

 farms are to be used in experiments Nos. i, 2, 4, 6, 9, 12, 14, 16, 17, 

 and 19, each student working with his own soil). 



Experiment No. 2. 

 Determination of the Capacity of Loose Soils to Absorb Water. 



To 100 grams of air dry soil in a beaker, add 100 cc. of water. 

 Mix the soil and water, then pour the mixture on a filter paper 

 fitted into a funnel and previously saturated, but not dripping. 

 For transferring the soil, 50 cc. more water may be used. Measure 

 the drain water in a graduate. To prevent evaporation, keep the 

 moist soil in the funnel covered with a glass plate. Deduct the 

 leachings from the total water used. Calculate the per cent, of 

 waiter retained by the air dry soil. 



Repeat the experiment, using sand, and note the difference in 

 absorptive power. 



Repeat, using 95 per cent, of sand and 5 per cent, of dry and 

 finely pulverized manure. 



Experiment No. 3. 



Determination of the Capillary Water of Soils. 

 For this experiment, a sample of soil directly from the 

 field is to be used. The sample is to be taken at a depth 

 of from 3 to 9 inches or at any depth desired. One hundred 

 grams of soil are weighed into a tarred drying pan, exposed 

 in a thin layer to the room temperature for twenty-four hours and 

 then reweighed. After an interval of from two to four hours the 

 soil is weighed again, and if the weight is fairly constant the per 

 cent, of water lost by air drying, representing the capillary water 

 of the soil at the time of sampling, is calculated. If desired this 

 experiment can be repeated, using different types of soil, as sand, 

 clay and loam. 



Experiment No. 4. 

 Capillary Action of Water Upon Soils. 



Firmly tie a piece of linen cloth over the end of along glass tube 

 4 inches in diameter, then fasten a piece of wire gauze over the 



