330 [Dec. 18, 



micrometer electrometer (Phil. Trans. 1839), and I had therefore 

 determined on taking the entire battery asunder, as well as in order 

 to attach fresh zincs to the copper cylinders. 



3. Previous to undertaking this somewhat tedious and troublesome 

 process, it occurred to me to try what effect would be obtained 

 from the discharge of the battery in carbonic acid vacua, by merely 

 recharging it with brine in lieu of rain-water : the result of this 

 experiment was such as to induce me for the present to forego my 

 intention of having new zincs, particularly as a very large number 

 of them were found to be much less oxidized than I had expected, 

 and rather to turn my attention to some improved mode of insulation. 



4. To accomplish this, the zincs were cleaned, and the old pieces 

 of string with which they were kept from metallic contact with the 

 copper cylinders were removed and replaced with new. The wood 

 trays, on which the battery is placed, were cleaned, and carefully 

 covered with a thick coating of shell-lac varnish, as were also the 

 glass cells, the latter having been first heated in a sandbath in 

 order to withdraw all trace of moisture before the varnish was 

 applied. 



5. On each tray slips of window-glass, also coated with shell-lac, 

 were fixed edgeways, forming a kind of rail on which the cells were 

 placed : the glass vessels being conical at the base, the strips of narrow 

 glass presented little more than four points of shell-lac on which each 

 cell rested. Those zincs which were found to be much oxidized 

 were placed aside ; and ultimately three batteries were completed, 

 each of 1120 pairs of plates, forming, when connected with each 

 other, one battery of 3360 cells : each cell was carefully charged 

 with a saturated solution of common salt and water, and the trays, 

 when placed on the racks, were separately insulated by resting on 

 pieces of ebonite. 



6. It will be observed that I have reduced my battery from 3520 

 to 3360 pairs of elements; the tension, as shown by the spark 

 discharge, was nearly the same as when it was originally charged ; 

 but I have observed, after the battery has rested for a short time, 

 the first discharge between the wire terminals in air appears to be 

 more dense, presenting the same appearance as the discharge of a 

 weakly-charged Ley den jar. The purport of this communication 

 is not, however, to describe the general effects obtained by the 





