E. J. Russp]LL AND J. A. Prescott 



95 



A simpler and more accurate method of checking the results and 

 observing the agreement is to take out the logarithms of y and c. 

 If the equation is true : 



1 



logy 



I.e. 



2-4 



1 



log 0+1-3, 



^°S^"2l^°^^'"^'^" 



Table V. Adsorption of P2O5 % *^^^' — Agdell B,— /rom which all 

 phosphate has been removed by extraction with H,2,^0^ followed hy 

 NaOH (p. 94). ' 



Time 24 hours. Temperature 23° C. 



50 gms. of soil to 1000 c.c. of solution. 

 Phosphoric acid alone. 



P2O5 added (mgs. per 1000 c.c.) 

 P2O5 found in solution (C) 



(mgs. per 1000c. c.) 



PjOs left in soil {y) (mgs. 



per 100 gms. of soil) 



69-1 

 36-6 

 650 



Equation obtained : y = 2 1 • 2 C3 ■ 2 , 



In presence of HCl '06 N. 



FjOj added (mgs. per 1000c. c. 

 PoOg found in solution (V) 



(mgs. per 1000 c.c.) 



P2O5 left in soil (y) (mgs. 



per 100 gms. of soil) 



43-4 

 131 

 60-7 



Equation obtained: y — 20-2 (72-4 , 



In presence of Citric acid N/10. 



P2O5 added (mgs. per lOOOc.c.) 

 P2O5 found in solution {C) 



(mgs. per 1000 c.c.) 



P2O5 left in soil (y) (mgs. 



per 100 gms. of soil) 



43-7 

 23-6 

 401 



Equation obtained : 2/ = 8-8C2'l. 



The amount of P2O5 left in the soil is calculated to mgms. per 100 gms. of soil so 

 as to facilitate comparison with tlie other results. The amount of soil actually used wan 

 50 gms. ; the experimental values for y were therefore one half of the figures here given. 



