IN THE SOLID AND LIQUID PHASES. JOHNSTONE. 193 



For greater values of resistance than 10 10 ohms, the 

 electrometer may be substituted for the galvanometer and 

 the apparatus connected as in figure 2. 



Earth 



The A. C. Bridge method 1 referred to, was used consider- 

 ably in this work. It consists of a network of two resistances 

 and two condensers connected with a source of alternating 

 current, (110V), as shown in figure 3. The electrometer was 

 of the Dolezalek type but was fitted with an aluminium needle. 



1 Journal de Physique ; Series 5, III, Jan. '13. 



