58 Faure's Secondary Battery. 



III. 60C.C. 



IV. 60 „ 



V. 60 „ 



VI. 60 „ 



Two Callans cells, 



70 minutes 



100 „ 



160 „ 



240 „ 



as compared with the above, gave 60 

 cubic c.c, in 220 minutes. 



Of four cells charged as before, three were taken out of 

 the acid and drained, then packed in a box with sawdust. 

 After three hours they seemed as strong as when first packed; 

 left for twenty-four hours, nearly all electric energy had 

 apparently disappeared. Replaced in their jars, they recovered 

 sufficiently to drive an electromotor, and to decompose water 

 rapidly. 



The cell which had not been touched was as strong after 

 twenty-four hours as when first charged. 



One cell which had been charged for two hours w T as 

 unrolled, and the plate which had been connected with the 

 negative end of the Callan was examined. 



On separating the felt so as to leave undisturbed the 

 coating of oxide on the lead plate, this oxide appeared of a 

 dirty white colour, and on lifting up this coating the surface 

 in contact with the metal presented the appearance of 

 pulverulent metallic lead. 



On the outer surface of the lead plate, charged from the 

 positive pole, a dark brown colour was observed. On the 

 inner surface a nearly black powder had been formed. 



The respective lead plates of the combination being then 

 placed on one another, pressed together, and the terminals 

 connected with a platinum wire, the latter became red hot. 

 On reducing the pressure much Jess heat was given out. The 

 lead plates were then roiled up, replaced in acid, and worked 

 out. These being again unrolled and examined, the coating 

 of material on the plate which had been connected with the 

 zinc, or negative, pole of the battery was found to have lost 

 its metallic appearance, and to have become of a dirty white 

 colour, both inside and oat. The coating of material on the 

 plate which had been connected with the positive pole of the 

 battery was not nearly so dark in colour as when charged. I 

 noticed after a week or so that the first charge of acid was 

 not sufficient to keep the secondary battery properly in 

 action, and that the latter required more primary current 

 to get the same effect. It, however, seemed to recover after 

 a time upon the addition of fresh acid of 1 in 10 strength. 



Before paper or parchment paper was used in the con- 



