1 66 



Journal of Agricultural Research 



surrounding the particles and to any oily substances that might be present. 

 The influence of this factor, however, must be extremely small, if any, 

 because when these soils were slightly damped the amount of water moved 

 was generally less or about the same as before. The common belief that 

 water moves more rapidly in damp than in dry soils is generally exag- 

 gerated. When a soil is damped to eliminate the factor of resistance to 

 wetting, its absorptiA^e power for water is decreased correspondingly, so 

 that one factor tends to counterbalance the other, and at the end the 



EXPLy^/V/^T/OA/: 

 ■ Waier moy^ed /"ram mo/'s/ ^o// 3/ ^O "c- A> cfry so// 3^ O "c. 

 „ » ., .. » » O'c. 7. » » »^^V. 



«— «„— — ., .. » » " " 20'c. »\ " ~ " O'c. 



.p- « « - " " " O'c. » " » •'20'c. 



Fig. 10. — Curve showing the percentage of moisture moved from a moist and warm column to a dry and 

 cold column of Miami clay, and from a moist and cold to a dry and warm column of Miami clay. 



results are about the samiC. Moreover, the soils which stubbornly resist 

 wetting are not very common. 



From the practical standpoint the results of the second part of the 

 present investigation are probably far more imjprtant than those of the 

 first part just discussed. These results show the remarkable fact that 

 when the dry soil is kept at 20° and 40° and the moist soil at 0° C, the 

 dry soil takes up very little, if any, water from the moist soil and that 

 this quantity of water absorbed decreases with a rise in temperature. 

 As will be seen from the data, the percentage of moisture absorbed by 

 the dry soil at 20° is in all cases greater than that absorbed at 40° C. 



