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STATE BOARD OF AGRICULTURE. 



Table S. Osmotic Pressure in Atmospheres for Depression of the Freezing Point to S.999 "C. 



The osmotic pressure corresponding to depression of hundredths of 

 degrees may be read directly from the table. Furthermore, for all practi- 

 cal purposes the first differences x 0.1 may be taken as 0.012 ; hence, pres 

 sure when a is read to thousandths of a degree may be at once determined. 

 Thus, suppose a to be 1.244. For a == 1.24° P = 14.92 atmospheres; 

 4 X 0.012 = 0.048; 14.920 plus 0.048 = 14.968, total osmotic pressure in 

 atmospheres. 



The lowering of the freezing point of the various soils then at the two 

 opposite moisture contents together with the calculated concentration in 

 p. p. m. of solution and the osmotic pressure in atmospheres that these 

 values of the freezing-point depression represent, are shown in Table 3 : 



