60 Mr. J. W. Swan. On some Voltaic Combinations [May 24, 



pared with the interior. When, however, the circuit was opened, it 

 almost instantly rose to 1 "25 volt. 



So far the experiments showed that, as chlorine is nearly or per- 

 fectly insoluble in fused chloride of lead, or in fused chlorides of 

 sodium and potassium, it is necessary in this case that the surface of the 

 carbon pole on which the cathion is deposited be alternately exposed to 

 the action of the gas and electrolyte. Many experiments confirmed 

 this conclusion. The exposed surface of the carbon tube in this 

 experiment amounted to only 10 or 12 sq. cm. 



Exp. 3. As in the arrangement last described, the use of a porous 

 pot and a clay tube was found to be objectionable, through the action 

 of the electrolyte upon them, an arrangement was devised by which 

 the use of the porous pot and tube were avoided. The details are 

 seen in fig. 4. The carbon tube serves as an electrode, and also for 

 conveying the chlorine to the electrolyte. To render it impervious 

 to the gas, it was surrounded by a close-fitting porcelain tube. This 

 tube was closed at the top by a paraffined cork, through which a 

 glass tube in connection with the chlorine supply was passed. The 

 remainder of the apparatus was the same as in Experiment 2, but 



FIG. 4. 



L- 



