IN THE SOLID AND LIQUID PHASES. — JOHNSTONE. 193 



For greater values of resistance than 10^° ohms, the 

 electrometer may be substituted for the galvanometer and 

 the apparatus connected as in figure 2. 



fartK 



The A. C. Bridge method^ 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, (llOV), 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. 



