Solutions of Copper Suljihate in Glycerine. 545 



the surface of the liquid in the test-tubes d d. The diameter 

 of these test-tubes was large compared with that of the 



tube a, so that any casual displacement of the ends of the 

 tube a had no effect on the resistance measured. This 

 was verified experimentally as was also the fact that the 

 height of the liquid in b had no effect on the resistance. 



For the higher values of the resistance the cell was con- 

 nected in series with a battery and a Broca galvanometer 

 and the resistance calculated " from the deflexion and the 

 voltage applied. For a few of the lower values the galvano- 

 meter was too sensitive. A resistance of 10 ohms was put 



Fig. 2. 



E 

 ■ — ,\_ ,1 



IO,OOOcc> 



^VWVWVWWWW*- 



<r> 



\Qu) 



in parallel with the unknown resistance R and the galvano- 

 meter. When a resistance of 10,000 ohms was put in series 

 in the circuit (fig. 2) the galvanometer deflexions were 



