6 DISTRIBUTION OF THE ACTIVE DEPOSIT OF 



Whole Plates. 

 Activity on cathode = .604.* 

 " anode = .294. 

 Percentage cathode activity = 67.3 

 Total activity on two plates = .89 



L *wer Portion Exposed. 

 Activity on cathode = .228. 

 " anode = .114. 

 Percentage cathode activity = 66.7 



Total activity = .33. 



Upper Portion Exposed. 

 Activity on cathode = .157. 

 " " anode = .076. 

 Percentage cathode activity = 67.3. 

 Total activity = .23. 



The size of the opening was about 22% of the total area 

 of the plates including the sides. The relative total activities 

 would show that the density of active deposit on the edges 

 was less than that on the flat portion of the plates. 



In general, fairly satisfactory results were obtained with this 

 type of vessel. However, some discordant results were obtained 

 which were hard to explain, but it was thought that the large 

 amount of insulating material surrounding the electrodes 

 might be the cause of these irregularities. 



A second type of vessel was therefore constructed which 

 avoided this difficulty as far as possible. End and side views 

 of this vessel are shown in Fig. 3. The plates, which were of 

 zinc, were made on the guard ring principle. The main 

 plates, A, 5.8 cm. square, were slipped into place and held 

 there by short lugs which engaged with clips on the back of 

 the guard plate, B. The guard plates were 13 cm. square 

 with an opening of 5.9 cm. square in the centre to receive the 



♦Arbitrary units. 



