Voltaic Batteries^ Sfc, 279 



cable. In some instances above, its amount is increased at 

 certain positions, in others diminished, in cases in which, as 

 yet, no apparent cause can be assigned for such an alteration. 

 But the recurrence of this phaenomenon, with ft certain de- 

 gree of regularity as to the positions at which it takes place, 

 indicates that it has its origin in one uniform cause, the nature 

 of which, however, so far, is wholly undetected. 



168. 5th inference. That in this alternation in the amount 

 of action, which is detected by the larger plates used in the 

 latter experiments to occur at several positions as we recede 

 from the zinc or generating point, we perceive an effect pre- 

 cisely similar, and in all probability identical with that already 

 detected in the former experiments upon the effects of distance, 

 as they were registered in tables, Nos. 5 and 6. The recur- 

 rence of this alteration at similar positions in both cases, in- 

 dicates that in the several instances it has its origin in one 

 common cause, whatever that cause may be. 



169. I would not omit at this moment to remind you of the 

 extent to which I consider myself indebted for a suggestion, 

 which, in no inconsiderable degree, has influenced the reason- 

 ing upon some of the facts derived from the previous experi- 

 ments, though that suggestion did not originate the experi- 

 ments themselves. You may remember that some time past, 

 whilst urging me to follow up some former inquiries, you 

 hinted it as your opinion that some phasnomena detected in 

 them would prove ultimately to be due to radiation. 



Although this was the extent of your communication, and 

 I was alike ignorant upon what grounds such a conjecture had 

 been founded, and whether or not you had entered upon any 

 investigations in accordance with it, yet an idea at once so 

 novel and elegant could not fail to exercise its due influence 

 upon any one then engaged in such pursuits. 



I am not prepared to say how far my own course of expe- 

 rimenting already devised might have led to a similar train 

 of I'easoning, since it is impossible that the mind could have 

 been divested of the influence of such an impression thus in- 

 cidentally conveyed. 



I need not say how fully I shall feel recompensed for the 

 labour of experiment, if the results thus obtained independ- 

 ently, shall be found in the end to be in accordance with 

 your own views of the nature and extent of this phaenomenon, 

 or shall agree with the results of any investigations of it upon 

 which you may yourself have entered. 



1 70. My own results upon this point seem finally to indi- 

 cate that this tendency to diverge is limited both in its extent 



