144 



KOLLOCK-SMITH — ELECTRO-ANALYSIS. 



[April 13. 



Copper. 



Nickel. 

 A nickel sulphate solution containing 0.4802 gram of metal in ten 

 cubic centimeters was used in the following experiments*, and after 

 finding that this quantity was completely deposited in the mercury 

 in twenty minutes with a current of 2 amperes and 7 volts, the rate 

 of deposition in succeeding periods of time was determined with a 

 current of 2.5 amperes and 6 volts. 



In 2.5 minutes 0.2017 gram of nickel was deposited. 



• On employing a current of 6 amperes and a pressure of 5 volts 

 the solution became colorless in four minutes. Not a trace of 



