408 Soil, Soil Solution and Freezing-Point Determinations 



for y„ being obtained in exactly the same way as for the sandy loam 

 soil. 



The curves both seem to be of the type 



r„ = civv, .... (5) 



where c and x are constant for any one curve, and M„ is total moisture. 



361 



32 



28 



24 



_ 20 



16 



S 12 



/ 



s^^ 



V-Oi^ 



-1 2 -3 4 -5 -6 7 -8 -9 1-0 



Free moisture, in fractions of 1',, for sandy loam, and Y^^ for clay 



Fig. 3. Relation between free water and total moisture for clay and sandy loam soils. 



To test this, a more convenient form of (5) is obtained by taking log- 

 arithms of each side : 



log y„ = logc + a;log.V„, ... (6) 

 but 1 „ = /'. i'gi' where/ varies from to 1. Hence equation (6) becomes 



log/+log F2i = logc + a;logilf„. . . (7) 

 To solve (7) for c and x convenient values of /and M„ to take from the 

 curve for sandy loam, are 



(/=-l,M„ = 8-5); (/=1-0,M„=21). 

 This leads to the values 



X = 2-55 ; log c = (log Y,^ - 3-366). 



