Dr. Beetz on the Elecfromotive Force of Gases. 89 

 Table {con/inued). 



The agreement between the observed and calculated values 

 is sufficient to place beyond doubt the position, that gas bat- 

 teries also follow the electromotor law of" Volta's tension series. 



The electromotive forces given in the following table are the 

 mean results of the observations. The platinum coated with 

 hydrogen is taken as the starting-point, the numbers opposite 

 the several substances indicate the electromotive force which 

 they excite when placed in one of the gas tubes, hydrogen 

 being placed in the other. To give a clearer idea of the ab- 

 solute value of the forces, those of platinum and zinc and pla- 

 tinum and copper have also been determined, referred to the 

 same starting-point, and added to the series. In determining 

 the mean, the observations VI., 6; VIII., 3; and IX., 3, 

 have been neglected for the reasons there stated. For the 

 sake of comparison, I have placed the series found by Grove* 

 opposite my own. 



31 '49 Chlorine. 

 27*97 Bromine. 



23-98 Oxygen. 

 21*33 Nitrous oxide. 

 21*16 Cyanogen. 

 20-97 Carbonic acid. 

 20*52 Nitric oxide. 

 20-50 Air. 



Chlorine. 



Bromine. 



Iodine. 



Peroxides. 



Oxygen. 



Nitric oxide. 



Carbonic acid. 

 Nitrogen. 



* Philosophical Transactions, 1845, p. 359. 



