.s7/i' \VI1.I.IA.M .S7A.1//-..Y.S I'.R.S. 26 1 



A CONTRIBUTION TO THE HISTORY OF 

 s I :< 'ONI > ARY BATTER I ES. 



BY C. WILLIAM SIEMENS.* 



The surprising effects realised by Faure give particular interest 

 at the present time to the general subject of secondary batteries, 

 and it may not be uninteresting to the members of this Section to 

 put before them an account of some early attempts in this direc- 

 tion with which I have been connected. 



The earliest and, as regards its principle of action, the most 

 perfect and admirable form of secondary battery is, I venture to 

 think, that proposed by Sir William Grove as early as 1841. It 

 consisted, as is well known, of two test tubes with a strip of 

 platinised platinum suspended in each from an electrode passing 

 through the tube, the two tubes dipping with their open ends into 

 a trough tilled with acidulated water. In passing a galvanic 

 current through such a pair, hydrogen is developed in the one tube 

 and oxygen in the other in the well-known proportions, and if the 

 battery be disconnected, and the electrodes be connected by means 

 of a wire, with a galvanometer of high resistance, it will be found 

 that a continuous current is produced, exceeding a Daniell element 

 in electro-motive force, which current continues to flow until the 

 whole of the gases accumulated previously in the tubes by means 

 of the galvanic current have recombined. The current so pro- 

 duced necessarily equals that by which the decomposition was 

 effected, hairing only losses by resistance, which, in the case of 

 Grove's gas battery, admit of the utmost reduction. The drawback 

 to any practical use that could be made of the Grove gas battery 

 is that the active surface of triple contact between the metal, the 

 acidulated water, and the gas is exceedingly small, and consequently 

 that the amount of current to be got from such a battery in a 

 given time is also too small for practical use. 



In the year 1852 the problem was put to me whether, by some 

 modification of the Grove gas battery, it would not be possible to 



* Paper read before Section A of the British Association for the Advancement 

 of Science, 5th September, 1881. 



