GAS BATTERY. 255 



The voltaic current generated by this battery I attributed 

 to chemical synthesis, of an equal but opposite kind, in the 

 alternate tubes, at the points where the liquid, gas, and pla- 

 tinum met, and the object of covering the platinum with the 

 pulverulent deposit * was to increase the number of these 

 points, the liquid being retained upon the surface of the 

 platinum by capillary attraction. 



The point which appeared to me at that time as most 

 important was the beautiful instance of the correlation of 

 natural forces exhibited by the fifth effect, in which gases by 

 combining and becoming a liquid transfer a force which is 

 capable of decomposing a similar liquid, and causing its con- 

 stituents to become gases, heat, chemical action, and electricity 

 being all mutually dependent. 



The apparatus with which I made the above experiments 

 being composed of some pieces of tubing which happened to 

 be in my laboratory, did not enable me to attain any pre- 

 cise accuracy of measure as to the volumes of gases absorbed, 

 or to prove that Faraday's law of definite electrolysis finds no 

 exception in the gas battery. Since that paper was written 

 I have, after some failures, constructed apparatus by which I 

 have been enabled to verify this law and to extend my re- 

 searches into the nature of gaseous voltaic action. I have felt 

 the more called on to multiply experiments on this subject, as 

 a letter has been published on the gas battery, written by an 

 electro-chemist for whose opinion I have much respect, which 

 attributes its action to a cause different from that to which I 

 assigned it. 



Soon after my original publication I received a letter from 

 Dr. Schcenbein, the substance of which has since appeared 

 in print.-)- Dr. Schcenbein there expresses an opinion that in 

 the gas battery oxygen does not immediately contribute to 

 the production of the current, but that it is produced by the 

 combination of hydrogen with water. I have recently heard 

 a similar opinion to that of Dr. Schcenbein expressed by other 



* For the method of effecting this see Mr. Smee's paper, Phil. Mag., April 

 1840. 



t Phil. Mag., March 1843, p. 105. 



