THE 

 LONDON, EDINBURGH and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[THIRD SERIES.] 



AUGUST 184.7. 



XIV. On a tiew Voltaic Battery, cheap in its construction and 

 use J arid more powetful than any Battery yet made; and on 

 a cheap substitute for the nitric acid o/' Grove's Platina 

 Battel y. By the Rev. N. J. Callan, Professor of Natural 

 Philosophy in the Royal College, Maynooth*. 



QOME time ago, whilst I was reflecting on the principle of 

 ^ action of Grove's and Bunsen's batteries, it occurred to me 

 that lead might be substituted for the platina of the former and 

 the carbon of the latter. I put into the porous cell of a Grove's 

 battery a piece of lead about y^thof an inch thick, two inches 

 broad and six inches long. I found that the voltaic current 

 produced by the lead excited by a mixture of concentrated 

 nitric and sulphuric acid was very powerful. 1 afterwards 

 compared the power of this leaden battery with that of a pla- 

 tina one of the same size, by sending through the helix of a 

 galvanometer, at the same time, but in opposite directions, the 

 currents produced by the two batteries. Both batteries were 

 charged with the same acids ; the lead and platina were ex- 

 cited by concentrated nitric and sulphuric acid, and the zinc 

 by dilute sulphuric acid. The current from the platina bat- 

 tery destroyed the deflection produced by the leaden one, and 

 caused an opposite deflection, which indicated that the former 

 current was about twice as strong as the latter. The two 

 batteries were left working for about three hours and a half. 

 At the end of that time the current from the lead was about 

 twice and a half as powerful as the current from the platina. 

 The quantity of lead dissolved during these three hours and 

 a half was very small. 



It struck me that by diminishing the action of the acids on 

 the lead, I might increase the power of the battery. I there- 

 fore covered a leaden plate with gold leaf, and coated another 



* Comniunicated by the Author. 

 Phil. Mag. S. 3. Vol. 3 1 . No. 206. Jug. 1 84-7. G 



