ON ELECTROLTSIS IN ITS PHYSICAL AND CHEMICAL BEAEINGS. 409 



August 18. — Another similar experiment, but with a little more NaHO added 

 to liquid in tube to make colour more distinct. No good observation could be ob- 

 tained of the SO4 progress this time, as it did not get up to the bend, but the H 

 progress was read. The tube was graduated in millimetres for this experiment. 

 45 volts applied. 



The double number in the middle column represents the two ends of a slope 

 into which the boundary threw itself as soon as the current was stopped : indicating 

 convection. A galvanometer deflection of 45° means a current of -009 ampere. 



In the last experiment the tube was not perfectly horizontal, and this may 

 have caused some disturbance. In future experiments the tube was carefully 

 levelled to begin with. 



Experiment on velocity of copper. 

 August 24. — Started an experiment with CUSO4 in both vessels, and in tube 

 some NaCl with a little K^FeCyg. But the indicator did not form a sharp boundary 

 across the tube, and the experiment was not very satisfactory. 65 volts applied. 



Experiment on the velocity of hydroxyl. 

 August 25. — Made an experiment on the rate of travel of the hydroxyl radicle 

 of NaHO, by using the closed CuSO^ vessel -with copper electrode as anode vessel, 

 and putting a solution of soda in the open (now) cathode vessel, fig. 10. The tube 

 contained NaCl (5 grammes in 100 cc.) with a little phenol-phthaUein not coloured as 

 jet with alkali. The appearance of colour was the thing to be observed as the HO 

 travelled against the current and attacked the NaCl. 65 volts applied to electrodes. 

 Tube 40-7 cm. long. For diagram of results see fig. 16. 



It would seem probable that there was some unknown misreading here ; probably 7 for 9. 



