before and after completion of the Voltaic Circuit, 299 



the same as is represented in fig. 6. Nothing can be more 

 decisive than that the static effects of tiie voltaic battery are 

 not due to the contact of dissimilar metals ; as in this arrange- 

 ment, only one metal, platinum is used; but this battery, 

 whose action is, in itself, so purely chemical, presents to us a 

 full corroboration of the static effects preceding the development 

 of chemical action. 



35. A series of forty cells, the same as are described in 

 Mr. Grove's paper*, were charged with oxygen and hydro- 

 gen ; these sensibly affected the gold-leaf electroscope, fig. 3. 

 This arrangement was kept charged for upwards of three 

 months. No decrease in the gas of the oxygen tubes could 

 be detected. Whenever the terminals were tested by the 

 electroscope, they invariably exhibited the usual signs of ten- 

 sion } but not the slightest chemical or dynamic effect could 

 be obtained until the entire circuit was completed. 



36. Here we have a batter}', the active elements of which 

 are two gases, which, with a closed circuit, immediately enter 

 into active chemical combination ; remaining for upwards of 

 three months in such a state of tension as at all times to affect 

 the leaves of an electroscope; but in which no amount of 

 chemical action could be detected whilst the circuit remained 

 open. 



37. It now became a matter of some interest to ascertain^ 

 firstif the minimum amount of series with which the gas bat- 

 tery charged with oxygen and hydrogen would exhibit static 

 effects ; and, secondly/, whether, when it was charged with 

 gases which do not enter into chemical combination, ani/ signs 

 of tension could be elicited. 



38. By careful arrangement I obtained an attraction in the 

 gold leaves of the electroscope (fig. 6) with a series of nine 

 pairs ; with twelve or fourteen, the effects are very distinctj 

 and required no very delicate manipulation. The series of 

 forty pairs was then charged with oxygen and nitrogen ; at 

 first the electroscope was affected, and chemical action as well 

 as dynamic effects were obtained with the closed circuit ; these, 

 however, were evidently due to impurities in the nitrogen (this 

 gas was obtained by burning phosphorus in common air; the 

 oxygen by electrolysis) : after keeping the circuit closed for 

 two days, these effects ceased, when not the slightest static, 

 chemical or dynamic actions could be detected; the volumes 

 of the gases remaining perfectly stationary, whether the cif'- 

 cuil was closed or open. 



39. From the preceding experiments we learn that, when 



* Philosophical Transactions, 1843, plate v. fig. 1 [or Phil. Mag. S. 3, 

 vol. xxiv. p. 27OJ. 



