48 Laws of the Elementary Voltaic Battery. 



Interval of repose, 4 minutes. 

 1st. obs. momentary def. -450° Perm., def. 103° 



2nd. " " " -400? " " 102 



3rd. " " " +390 " " 102 



4th. « « " =400 " " 102 



Result, 400 mom. def. and 102 perm. def. 

 2nd. set. — Interval of repose, 1 min. between immersions in all the 

 observations. Period of exposure in solution, 1 min. 



1st. obs. momentary def. +330° Perm. def. 100° 



2nd. " " " —340 " " 100 



Result, 336 mom. def. and 100 perm. def. 



Period of exposure in solution, 2 min. 

 1st. obs. momentary def. —300° Perm. def. 99° 



2nd. " " " -260 " " 98 



Srd. " " " +240 " " 96 



Result, 250 mom. def. and 97 perm. def. 



Period in solution, 4 min. 

 1st. obs. momentary def. +200° Perm. def. 95° 



2nd. " " " -230 " " 94 



3rd. " " " -220 « " 93 



Result, 210 mom. def. and 94 perm. def. 



Period in solution, 8 min. 

 1st. obs. momentary def. —180° Perm. def. 91° 



2nd. " " " +160 " " 90 



2rd. " " " =170 " " 90 



Result, 170 mom. def. and 90 perm. def. 



III. Relative influence of the zinc and copper. 



9. The effect of repose out of the solution to exalt the activity of 

 voltaic plates, although a fact generally observed, does not appear 

 hitherto to have been made the subject of systematic examination. 

 From the foregoing experiments, it is evident that the electrical en- 

 ergy of the plates as measured by the momentary deflection, contin- 

 ued to augment as the interval of repose out of the solution was in- 

 creased, until this interval was extended to 2 hours, with which the 

 experiments (7), were terminated. A single observation, made the 

 following day, with the same plates and liquid, as were used in the 

 ■experiments (7), gave a deflection very little greater than in the ex- 

 periments with an interval of 2 hours. It would therefore, appear, 

 that plates which have been subjected to the action of the solution 

 for some time, do not recover their power of producing momentary 

 deflection, until they have been out of the liquid two or three hours. 



