478 Mr. "W. C. M. Lewis : Experimental Investigation 

 Hence 



tttt, -j- =5*4 X 10~ 9 gram BaCL per cm. 2 , 



lil dc =-E — - 



or 1-6 x 10~ 9 grin, chlorine, 



Tci (found) 3> 10 — 8 grm./cm. 2 



The result obtained here is of too qualitative a nature to 

 •show whether there is agreement or not. 



Adsorption of Copper Chloride. 



With this substance both copper and chlorine were sepa- 

 rately estimated. 



The Adsorption of the Copper : — 



The oil-surface area was 8000 cm. 2 The copper in the 

 solution was estimated electrolytically, both before and after 

 the adsorption. The change in weight of the electrode was 

 only 0'2 milligram. 



Hence 



r Cu = 2-5 x 1(T 8 grm./cm. 2 



A repetition of the determination gave 

 or "mean value 



r Cu = 4-5 x io- 8 , 



r Cu == 3*5 x 10 gram per cm. 2 



Estimation of the Chlorine : — 



As in previous cases, this was estimated as silver chloride. 

 The difference in weight of the AgCl precipitate was 6 milli- 

 grams. The surface-area = 8000 cm. 2 , and hence 



r ci = 1-8 x 10~ 8 grm./cm. 2 



A repetition of the determination gave 

 r cl = 2-3xl0~ 8 ; 



so that the mean value is 



r ri = 2 x 10~ 8 grm./cm. 2 

 Hence 



r Cu + T C1 = 5-5 x 10~ 8 grm./cm. 2 



