at the Electrodes in a Solution. 



65 



Ail the experiments on solutions B, C, D, and part of 

 those on E were carried out in apparatus 2. It consisted of 

 a polarimeter-tube. The top being originally bevelled had to 

 be ground perfectly flat. The cathode consisted of a copper 



Fijy. 2. 





m 



^ 



>J}node 



plate which was made perfectly flat, then polished and finally 

 amalgamated. This was done by cleaning it with nascent 

 electrolytic hydrogen, after which it amalgamated extremely 

 readily, on dipping it into mercury. It was then again 

 polished on perfectly clean chamois-leather, excess of mercury 

 being removed from the edges by a pipette, drawn out to a 

 fine point. This process of cleaning and polishing was 

 repeated after each experiment. In order to avoid any 

 liquid coming between the cathode and the surface ol the 

 glass forming the end of the tube by capillary action, this 

 was greased with a trace of vaseline, so much only as could 

 not be removed by a piece of dry filter-paper. The cathode 

 was always fixed on the apparatus before introducing the 

 liquid, by placing it in the cap, into which it fitted accurately, 

 Phil. Mag. S. 6. Vol. 1. No. 1. Jan. 1901. F 



