54 Mr. T. A. Malone on the Gas Battery of Mr. Grove ; 



division (that connected with the copper of the battery) will 

 have double the quantity of sulphate of copper in solution that 

 it had at the commencement. 



There is no doubt but the polar theory with the mutual 

 transfer of elements is simple and beautiful, and has become 

 popular ; but a theory, to be correct, must adapt itself to facts. 

 I have seen nothing yet to explain away the facts pointed out by 

 the late Professor Daniell, Dr. Miller, and myself, and take this 

 opportunity to draw the attention of Professor Williamson and 

 others interested in such inquiries to the subject, in hope of 

 getting further information. 



I am, yours truly, 



James Napier. 



X. On the Gas Battery of Mr. Grove ; and its Theory. By 

 T. A. Malone, late Director of the Laboratory , London Insti- 

 tution*. 



HAYING had, during the past summer, occasion to review 

 minutely the theory of the voltaic pile, I was, by the 

 nature of my work, led to go somewhat fully into an examina- 

 tion of recorded facts and observations in regard to the whole 

 subject — and this by various writers, chemical and electrical, 

 old and modern. The results of my inquiry and attendant 

 experiments have compelled me to lay down different interpreta- 

 tions of the origin of the power and nature of the phenomena of 

 the pile from those usually adopted by the advocates of the che- 

 mical and contact theories, or of the theory of Davy, which 

 makes both contact-electrical and chemical action essential to 

 the origin and continuance of the current. Nevertheless I may 

 in passing observe that, with an important qualification as to 

 the origin of the electric agency, I incline to a revival of the 

 latter theory. My reasons for doing so will be apparent a little 

 later. I know, however, that with respect to the theory of the 

 voltaic pile, speaking generally, I dare not at present express 

 fully my scientific convictions, since the facts on which I rely are 

 in part secondhand, and, although the work of eminent men of 

 former days, may be thought by some to need revision on account 

 of our extended knowledge. At the same time it is right to say 

 that I have no doubt as to the consequences of such revision. 

 But with regard to the gas battery considered by itself, I have 

 no such cause for hesitation ; there everything of a chemical 

 and electrical nature essential to the inquiry is apparently so 

 open and under control and ready observation, that I do not see 



* Communicated by the Author. 



