618 



In order to protect the Ag-AgCl-electrodes from the light, the 

 fliisks F^ and F. are externally coated with a fihii of red gehitin 

 obtained by inserting them in a solution of gelatin to which a little 

 eosine had been added and which had just started to gelatinise. 

 IMoreover, thev were ahvays protected from direct daylight. 



3. Method and preUininary experiments. The measurements were 

 made a few^ minutes after the pressure had set in. A number of 

 measurements at difïerent pi-essures were always made. When between 

 two measurements the liquid had to be pressed back from tlask F^ 

 to flask 7^1 (for which at (/ the connection witli the pressure arrange- 

 ment could be broken oif and an oil suction pump attached), no 

 measurements w'ere executed at suction pressure. 



From Grumbach's experiments we notice that the value of the 

 current potentials varies a little during tiie tirst days after the con- 

 struction of a battery F^F^. I repeated one of his observations, also 

 with the object of comparing the results obtained with his and my 

 own apparatus. 



Table I contains the results of a series of measurements carried 



