1882.] Mr. H. Sutton. New Electrical Storage Battery. 257 



A few specimens of lead or flint glass were examined in the same 

 way, and in this case a very marked connexion "between electric con- 

 ductivity and density was observed. This result was, however, no 

 doubt due to the fact that the density of this kind of glass gives an 

 indication of its chemical composition. In all the specimens examined 

 it was found that the higher the density the lower the conductivity. The 

 highest density reached, however, was that in the case of a Thomson's 

 electrometer jar, which had a density of 3 - 172. On examining these 

 specimens for chemical composition it was found that the electrometer 

 jar contained almost exactly the proper amount of lead and potash to 

 form a trisilicate of potash and lead. It appears likely, therefore, 

 that the electric conductivity of glass is lowest when it is an exact 

 chemical compound. It will be interesting to learn from future ex- 

 periments if still more dense glass has a higher conductivity, and if 

 the conductivity passes a minimum at the point where the pure 

 silicate is reached. 



The author has to express his great obligation to his colleague, 

 Dr. Edward Diver, in whose laboratory and under whose superin- 

 tendence the chemical analyses of the specimens of glass were made. 



Ill . <: On a New Electrical Storage Battery. (Supplementary 

 Note.)" By Henry Sutton. Communicated by The 

 President. Received January 3, 1882. 



The new cell consists of a flat copper case, of the same shape as a 

 Grove's cell ; it has a lid of paraffined wood, from which hangs a plate 

 of lead amalgamated with mercury, the lower part of the lead plate 

 being held in a groove in a slip of paraffined wood resting on the 

 bottom of the copper case : through the lid a hole is bored for the 

 introduction of the solution, which consists of a solution of cupric 

 sulphate, to which is added one-twelfth of hydric sulphate ; the pre- 

 sence of this free sulphuric acid improves the cell at once. 



The following sectional sketch shows the arrangement : — 



