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THE ROYAL SOCIETY OF CANADA 



of each cycle contact is made: during one- third of the time, it is 

 broken. The depth at whiich contact is made can be varied by 

 adjusting the glass tube in G up or down; thus the time of contact 

 in each cycle can be varied as desired. The frequency of the cycles 

 can be adjusted from anywhere between one a second to one in several 

 hours. 



The mercury in G is covered with water which moves up and 

 down above it and when contact is broken the mercury is not oxidized 

 even when high voltages are directly applied. The movement of the 

 mercury in G and D is dampened by having only a small opening to the 

 air at the top of tube G. The apparatus as described has been used 

 continuously for several months without any adjustment being 

 necessary. A current of 4 amperes at 110 volts was employed. 



Department of Chemistry, 

 McGill University. 



