Laws of the Elementary Voltaic Battery. 45* 



any thing like precision. The proper permanent effects have not, as 

 far as we are informed, been the subject of any observation at all, 

 inasmuch as it has been usual to get the deflection as early as possi- 

 ble without regard to the interval between the plunge and the instant 

 of observation. 



It is this omission to distinguish these two effects, that has led the 

 able and ingenious contriver of the torsion galvanometer, in his ex- 

 periments with it, upon the elementary battery, to erroneous conclu- 

 sions regarding the law which expresses the connexion between the 

 degree of deflection and the quantity of surface immersed. — It is 

 made apparent from the following experiments that the momentary 

 and permanent deflections obey different laws, and that in many 

 cases when the momentary deflections augment in successive im- 

 mersions of the plates, the degree of deflection measured one or two 

 minutes after immersion is unchanged. Nothing could be more 

 striking during these observations than the prodigious velocity with 

 which the deflecting energy declined, making it impossible often even 

 with the most adroit movement of the torsion key, to follow it j nor 

 on the other hand can any thing surpass the remarkable steadiness of 

 the deflection when one or two minutes have elapsed. All the at- 

 tempts, therefore, at determining the momentary deflections are attend- 

 ed with more or less of uncertainty from this great rapidity with 

 which the electrical action, or at least so much of it as is measured 

 by deflection, decreases for the first few instants. Hence, in the 

 experiments which follow, nothing more than an approximation to 

 the two first actions is aimed at. It is this uncertainty as we believe, 

 which renders of no value, all determinations which are not based on 

 the subsequent or permanent deflections, as a measure. 



7. In the first set of experiments the momentary effects have beem 

 measured as nearly as practicable, by taking an observation immedi- 

 ately upon immersion ; leaving the plates one minute in the liqui-d ; 

 then removing them for some time, and immersing them a second 

 time, and at the instant of immersion, taking another obsevation. 



At the end of each plunge, that is, after one minute of action — the 

 effect was also observed. The following results indicate that the 

 Jirst effect augments as the interval between the plunges is increased. 

 — They also go to prove that the permanent deflection very ^owly 

 declines. 



The plates having first been immersed for some time in the solu- 

 tion, were removed for 5 minutes, and then plunged twice in succes- 

 sion at an interval of 5 minutes. 



