1873.] Messrs. Gladstone and Tribe on an Air-Battery. 247 



homologous series of " oxycarbons," of which the unit of carbon with the 

 weight 12 may be regarded as the first term, and of which the adjacent 

 terms differ by an increment of carbonic oxide (CO) weighing 28, pre- 

 cisely as homologous series of hydrocarbons differ by the increment CH 2 

 with the weight 14. I have succeeded in identifying by analysis two at 

 least of these substances, namely the adjacent terms C 4 3 and C.0 4 . 

 From this point of view these peculiar bodies are members of a series of 

 oxycarbons analogous in the oxycarbon system to the series of hydro- 

 carbons of which the unit of carbon is the first and the unit of acetylene 

 C 2 H 2 is the second term, the oxycarbon C 4 3 being represented in that 

 series by the hydrocarbon crotonylene C 4 H 6 , and the oxycarbon C 5 4 by 

 the hydrocarbon valerylene C 5 H 8 . 



III. " On an Air-Battery By J. H. Gladstone, Ph.D., F.R.S., 

 and Alfred Tribe, F.C.S. Received March 6, 1873. 



The galvanic battery which we are about to describe is founded on a 

 reaction that we brought under the notice of the Royal Society last 

 spring*. We then showed that if pieces of copper and silver in contact 

 are immersed in a solution of nitrate of copper in the presence of 

 oxygen, a decomposition of the salt ensues, with the formation of 

 cuprous oxide on the silver and a corresponding solution of the copper, 

 while a galvanic current passes through the liquid from copper to silver. 

 We stated, moreover, that this was no isolated phenomenon, but only 

 one of a large class of similar reactions. It seemed desirable to 

 examine more fully the history and the capabilities of the electrical 

 power thus produced. 



It was previously ascertained that the combination of the oxygen 

 takes place only in the neighbourhood of the silver ; and the following 

 formulae may serve to render the chemical change and transference 

 more intelligible : — 

 Before contact, 



m Ag + + Cu2N0 3 + Cu2N0 3 + nCu ; 



after contact, 



mAg + Cu 2 + Cu2N0 3 + Cu2jN t 3 +0-2) Cu. 



This action is evidently a continuous one until either the oxygen or the 

 copper fails. 



Now the oxygen of the atmosphere is practically unlimited in amount, 

 but there is a difficulty in bringing any large quantity of it into contact 

 at once with the silver and the dissolved salt. 



To facilitate this, we arrange that the silver plate should have a 

 horizontal position just under the surface of the liquid in the cell ; and, 



* Proc. Eoy. Soc, April 1872, vol. xx. p. 290. 



