464? 



Voltaic Battery, with a view of ascertaining the rationale of its Ac- 

 tion and on its application to Eudiometry." By William Robert 

 Grove, Esq., M.A., F.R.S., &c., was resumed and concluded. 



The author, referring to a paper published in the Philosophical 

 Magazine for December 1842, giving an account of a voltaic bat- 

 tery of which the active ingredients are gases, and by which the de- 

 composition of water is effected by means of its composition, de- 

 scribes several variations in the form of the apparatus recorded in 

 that paper. The experiments he has made with this new apparatus, 

 and the details of which occupy the greater part of the present 

 memoir, he conceives establish the conclusion that the phenomena 

 exhibited in the gaseous battery are in strict conformity with Fara- 

 day's law of definite electrolysis. They also confirm him in the 

 opinion which he had expressed in his original paper, and which 

 had been controverted by Dr. Schoenbein, in a communication to 

 the Philosophical Magazine for March 1843, as well as by other 

 philosophers, namely, that the oxygen, in that battery, immediately 

 contributes to the production of the voltaic current. Besides em- 

 ploying as the active agents oxygen and hydrogen gases, he extends 

 his experiments to the following combinations : namely. 



Oxygen and peroxide of nitrogen ; 



Oxygen and protoxide of nitrogen ; 



Oxygen and defiant gas ; 



Oxygen and carbonic oxide ; 



Oxygen and chlorine ; 



Chlorine and dilute sulphuric acid ; 



Chlorine and solutions of bromine and iodine in alternate tubes ; 

 Chlorine and hydrogen ; 

 Hydrogen and carbonic oxide ; 

 Chlorine and olefiant gas ; 

 Oxygen and binoxide of nitrogen ; 



Oxygen and nitrogen, with solution of sulphate of ammonia ; 

 Carbonic acid and carbonic oxide, with oxalic acid as an electro- 

 lyte; 



Hydrogen, nitrogen, and sulphate of ammonia. 



The author concludes, on reviewing the whole of this series of 

 experiments, that, with the exception, perhaps, of olefiant gas, which 

 appears to give rise to an extremely feeble current, chlorine and 

 oxygen, on the one hand, and hydrogen and carbonic oxide, on the 

 other, are the only gases which are decidedly capable of electro- 

 synthetically combining so as to produce a voltaic current. He 

 thinks that the vapours of bromine and of iodine, were they less 

 soluble, would probably also be found efficient as electro-negative 

 gases. 



He proceeds to consider, in the remaining part of his paper, the 

 application of the gas battery to the purposes of eudiometry, founded 

 on the circumstance already mentioned, that nitrogen gas, as well 

 as several other gases, are absolutely without effect in as far as re- 

 gards any alteration of their volume, and may therefore be ad- 

 vantageously employed in the analysis of atmospheric air, or other 



