1879.] 



The Chloride of Silver Battery. 



281 



November 20, 1879. 



THE PRESIDENT in the Chair. 



In pursuance of the Statutes, notice of the ensuing Anniversary- 

 Meeting was given from the Chair. 



Mr. George Matthey was admitted into the Society. 



Mr. Bramwell, Mr. Busk, Mr. De La Rue, Mr. JSTewmarch, and 

 Mr. Perkin, having been nominated by the President, were elected by 

 ballot Auditors of the Treasurer's Accounts on the part of the Society. 



The Presents received were laid on the table, and thanks ordered for 

 them. 



The following Papers were read : — 



I. " Experimental Researches on the Electric Discharge with 

 the Chloride of Silver Battery." By Warren De La Rue, 

 M.A., D.C.L., F.R.S., and Hugo W. Mijller, Ph.D., F.R.S. 

 Received August 7, 1879. 



(Abstract.) 



Pakt III. — Tube-Potential ; Potential at a Constant Distance and 

 Various Pressures ; Nature and Phenomena of the Electric Arc. 



In the first part of this paper the authors describe a series of experi- 

 ments to determine the potential necessary to produce a discharge in a 

 tube, exhausted gradually more and more while using a constant 

 number of cells in all the experiments. In consequence of the life of 

 the battery becoming so much exhausted by the method employed, the 

 experiments were confined to one gaseous medium, namely, hydrogen. 

 Since the completion, however, of the measurements described in the 

 paper, the authors have found two other more convenient methods for 

 determining the tube-potential, which do not exhaust the battery 

 injuriously; these are described in an appendix. The tube, 162, em- 

 ployed was 33 inches long and 2 inches in diameter, the distance 

 between the ring and straight wire terminals being 29*75 inches; the 

 battery consisted of 11,000 cells. The discharge took place when the 

 pressure was reduced to 35*5 m.m., 46,710 M, and the exhaustion was 

 afterwards continued gradually until it fell to 0*0065 m.m , 8*6 M- 

 In commencing each set of experiments the deflection of a tangent- 

 galvanometer was observed when the battery was short-circuited. By 



VOL. xxix. x 



