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XLI. On the Gas Voltaic Battery. — Experiments made with 

 a view of ascertaining the rationale of its action and its ap- 

 plication to Audiometry. By W. R. Grove, Esq., M.A., 

 F.R.S., Professor of Experimental Philosophy in the London 

 Institution*. 



TN the Philosophical Magazine for December 1842, I have 

 published an account of a voltaic battery in which the 

 active ingredients were gases, and by which the decomposi- 

 tion of water was effected by means of its composition. 



The battery described in that paper consisted of a series of 

 tubes containing strips of platinum foil covered with a pulveru- 

 lent deposit of the same metal ; the platinum passed through 

 the upper parts of the tubes, which were closed with cement, 

 the lower extremities were open ; they were arranged in pairs 

 in separate vessels of dilute sulphuric acid, and of each pair 

 one tube was charged with oxygen, the other with hydrogen 

 gas, in quantities such as would allow the platinum to touch 

 the dilute acid ; the platinum in the oxygen of one pair was 

 metallically connected with the platinum in the hydrogen of 

 the next, and a voltaic series of fifty pairs was thus formed. 

 With this battery the following effects were produced : — 



1st. A shock was given which could be felt by five persons 

 joining hands. 



2nd. The needle of a moderately sensitive galvanometer 

 was whirled round and remained permanently deflected 60°. 



3rd. A gold-leaf electroscope was notably affected. 



4th. A brilliant spark visible in broad day-light was given 

 between charcoal points. 



5th. Iodide of potassium, hydrochloric acid, and water 

 acidulated with sulphuric acid were severally decomposed ; 

 the gas from the decomposed water was collected and deto- 

 nated. The gases were evolved in the direction which the 

 chemical theory would indicate, the hydrogen travelling in one 

 direction throughout the circuit, and the oxygen in the reverse. 



When distilled was substituted for acidulated water in the 

 battery cells, the effects were similar but more feeble. 



The effects, though clear and decisive in themselves, were 

 further tested by counter experiments, such as reversing the 

 current by reversing the gases, &c; but these I need not here 

 detail, as the electrical effects of the gas battery, when charged 

 with oxygen and hydrogen, have since the publication of that 

 paper been repeatedly verified. I further stated, that when 

 carbonic acid and nitrogen were substituted for oxygen and 



* From the Philosophical Transactions for 1843, part ii. ; having been 

 received by the Royal Society March 27, and read May 11, 1843. 



