474 



Transactions. 



Further trials of a similar nature were made with other soils, and the 

 results of these were of the same general form. Two typical sets of results 

 are given below- — 



Table VII. — Absorption of Lime from Lime-water by Wangantji Soils. 



Initial Concentration 



Grammes Ca(OH) 2 



per Litre. 



Final Concentration : 



Grammes Ca(OH) 2 



per Litre. 



Loss of Concentration 



Grammes Ca(OH)o 



per Litre. 



Constant : k. 



Soil A. 



1-558 



1-2984 



1-0388 



0-7792 



0-5196 



0-2600 



0-7479 

 0-5651 

 0-3513 

 0-2440 

 0-1300 

 00444 



Soil B. 



Average value of soil A, 0-104. 



Average value of soil B, 0-094. 



tf6 



5 



a. 



1-4 



ConcentraUon SoIuX-lotu: Cms. C-a, I0HU per htre. 

 Fig. 4.— Soil A. 



CoTLCcntrahjorv Solution EquiUbrumv 

 Gm-s. CatOHi^ per LUre 



Fig. 5.— SoH B. 



It will be noticed that the graphs are of quite similar form to those 

 previously obtained, and the values of the constants for any set show 

 approximate agreement. In certain cases, however, it would seem that 

 this relationship ceases to hold when the concentration becomes very small. 



Time curves : In preliminary experimentation we had obtained some 

 information as to the rate at which the reaction proceeds with varying 

 initial concentrations ; and it was decided to investigate this more fully in 

 the hope of deducing further confirmatory evidence. Typical sets of values 

 are as follows : — ■ « 



