ROSA AND WOLFF : INTERNATIONAL ELECTRICAL UNITS 265 



In all the experiments with the silver voltameter, the strength 

 of the current was maintained constant at the value of approxi- 

 mately 0.5 ampere, the length of time of its passage being two 

 hours, and the weight of silver deposit being slightly greater than 

 4 grams. 



The delegates originally employed the silver nitrate and the 

 voltameters which they brought with them and carried out the 

 work under experimental conditions similar to those used by 

 them ordinarily in their respective laboratories. 



In the greater part of the experiments Dr. Jaeger used a form 

 of voltameter employing silk and a glass cup, to separate the 

 anode from the cathode. 



Mr. Smith employed the arrangement designated by him by 

 the name of "the new form." 



Dr. Rosa made use ordinarily of the porous pot of porcelain. 



M. Laporte employed the filter paper form. 



In some of the experiments, certain of the delegates exchanged 

 materials and used the apparatus of one another. 



While the delegates carried out their experiments, members 

 of the Bureau of Standards, under the direction of a subcommit- 

 tee, made other experiments on the silver voltameter, with the 

 end in view of studying the different electrolytes and forms of 

 voltameter used. 



Summary of Results of 89 Deposits, Excluding Relative Values of 



Experiments 1, 14, and 16 



1. With Voltameters Using Porous Cups or without any Septum (with Electrolyte 



neutral by the iod-eosine test and free from reducing substances 



by the permanganate test) 



(1) Mean of 10 1 deposits, NPL, new form voltameter 1.01831i 



(2) Mean of 4 deposits, NBS, porous cup, large voltameter 28 9 



(3) Mean of 9 deposits, NBS, porous cup, small voltameter * . . 28 6 



(4) Mean of 1 deposit, NBS, porous cup, medium voltameter 28» 



Mean 24 deposits, two types, several sizes of voltameters 1.01829 



Mean excluding two determinations with unsteady current 1.01828 



« 



1 Two deposits in NPL, new form, in seventh experiment, gave 1.01841 g . The 

 current in this experiment was unusually unsteady. If these two determinations 

 be excluded, the mean of 8 deposits is 1.01828? and the mean of 22 is 1.01828o 



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