with the Mercury Cathode. 



377 



reduction (exp. 8) is made sufficiently long to reduce all the 

 silver chloride, there seems to be no difficulty in a subsequent 

 complete reduction. 



The most satisfactory method, then, for the removal of the 

 silver chloride on the anode is reduction by hydrogen in the 

 porcelain crucible at a temperature of 500-600°, and the time 

 required is about 20 minutes. This method has the added 

 advantage of allowing the same silver-covered anode to be used 

 over and over again without repeating. 



Liquid op the Inner Cell. 



Alkalinity. — Hildebrand* states that the inner cell after 

 electrolysis contains nothing but pure water. Smith, f appar- 

 ently quoting Hildebrand, makes a statement to the same effect. 

 Goldbaum^: speaks of the possibility of decomposition of the 

 sodium amalgam in the inner cell, giving rise to sodium 

 hydroxide. In the writer's experience the liquid of the inner 

 cell, after electrolysis had begun, was alkaline to indicators 

 whenever tested. In one experiment a drop of phenolphthalein 

 was added to the inner cell liquid. Upon passing the current 

 the liquid turned pink and remained alkaline throughout the 

 electrolysis. In a second experiment the inner cell liquid, col- 

 ored pink by the same indicator shortly after the electrolysis 

 had begun, stayed pink during the remainder of the operation. 



In a number of experiments the alkalinity of the inner cell 

 was determined by titration with -08996N sulphuric acid using 

 methyl orange. The amounts of acids used together with the 

 initial and final current conditions are given in Table IV as 

 follows : 



Sulphuric 



acid Time of 



•08996N electrolysis 

 No. cm 3 inin 



Table IV. 



Amp. Voltage 



initial & final initial & final 



13-69 



8-66 



2-39 

 2*38 

 2*15 

 2-09 



131 



1-01 



•92 



140 

 70 



14 



18 

 19 

 18 



42 



38 



13 



•24--035 



•28--063 



1-4 -0-1 

 1-4 -0-1 

 1-3 -0-09 

 1-1 "7-0-1 



4 cells 



4-3 



7-2-8 

 7-2-8 

 7-2-8 

 7-4-8 



Eemarks 



Changed 

 during expt. 



77- -03 4 cells 

 03 6-8 



(•>:■: o;; 7*4-8 



Lo }- 



•6 Raised to 1-0 

 near the start 



10 -62 31 



* L. c. 452 and 453. 



1-3 --03 

 + L. c. 305. 



7-8 



% L. c. 41. 



Am. Jour. Sci. — Fourth Series, Vol. XXXII, No. 191. — November, 1911. 

 28 



