ÖFVERSIGT AF K. VETENSK.-AKAD. FÖRHANDLINGAR 1898, N:0 7. 399 



variation of temperature was not given. 3rd. The two curves 

 given were expressed as follows: — 



[ [ ampere hours per kg. of 



j abscissae: ! peroxyde plate or so called 

 for plates 10 and 6 mm.; \ positive plate. 



ordinales: (density, of sulpliuric acid 

 in degrees Baume. 



thick respectively. 



I objected to the nature of the abscissae and recalculated 

 the curve for the 10 mm. plates in function of the abscissae for 

 the 6 mm. plates, and obtained the curve drawn as a dojtted 

 line. I wanted to get at the ratio between the capacities of 

 two plates of equal dimensions except in as far as the thickness 

 was concerned. My mode of recalculation was simple. Suppos- 

 ing that the weights of the plates varied as the thickness which 

 I knew to be approximately true, I had only to multiply the 

 capacities given for the 10 mm. plates by 10 : 6 in order to 

 reduce them from capacities per kg. to capacity per 10 mm. 

 plate of the same dimensions as a 6 mm. plate weighing one 

 kg. The dotted curve represents the result — and takes away 

 the apparently paradoxical anomalies of the result sent from 

 Paris which gives lower »capacities» för the thicker plates as 

 well as intercepting places etc. The curves in Fig. 1 give the 

 mean P. D. at the terminals of the cells during the experi- 

 ments. I wish to point ont that an excess of negative or spongy 

 lead plate was used in order to limit the variations to the posi- 

 tive or peroxyde plate as much as possible. If we now comtem- 

 plate the nature of these curves, we find that they shew a 

 capacity of zero for a current of 1 arap. per kg. 6 mm. plate, 

 when the electrolyte has a finite concentration, then the capa- 

 cities rise to two maxima which occur at the concentrations 

 27 • 5°B and 31 • 5°B respectively, then the capacities fall with 

 the increasing density. Why should now the capacity of the 

 cell be limited to zero when the acid is a good conductor viz: — 



for 6 mm. positive plates at 5°B approx., and 

 » 10 mm. » » » 9° B » ? 



