C. T. R. Wilson, On a Micro-voltameter 345 



On a Micro-voltameter. By C. T. R. Wilson, M.A., Sidney 

 Sussex College. 



[Read 19 May 1919.] 



Experiments were described with a mercury voltameter, in 

 which one elctrode consists of a sphere of mercury deposited on 

 the end of a fine platinum wire and measured by means of a 

 microscope. Quantities of electricity varying from a few hundred 

 electrostatic units to about one coulomb may be measured by it. 

 The almost instantaneous change of size of the drop when a 

 capacity of one tenth of a microfarad, charged to 1 volt, is dis- 

 charged through the instrument is easily observed. A magnet 

 inserted in or removed from a coil connected to the terminals of 

 the voltameter produces an easily measured effect. Experiments 

 were also mentioned which suggest the possibility of its application 

 in measurements of much smaller electrical quantities. 



