MEASUREMENTS WITH ZINC AMALGAMS. 



33 



Potentials of Zinc Amalgams. Preliminary Series (Cell I). 



The sum of the first three potential differences must equal the fifth ; other- 

 wise a cyclic system furnishing work in violation of the laws of energy would 

 be conceivable. As a matter of fact, their sum is 0.051775 instead of 0.05173, 

 the sum of (a) and (b) is 0.033645 instead of 0.03363; the sum of (b) and 

 (c) is 0.03566 instead of 0.03563. From an analysis of these figures it is 

 clear that the values recorded in the first three cases are all too high ; the 

 error is more than 0.00001 volt in every instance. 



Some constant defect, either in the potentiometer or in the method of 

 using it, is indicated ; but as this was the first time that formal measurements 

 were made with the instrument, these errors may be excused if they do not 

 occur again, and the results may be acceptable so far as they agree with 

 the others. That both these conditions were satisfied will be evident on 

 examination of the rest of the work. 



The measurements of other similar cells were made with even greater care, 

 and are recorded below : 



Concentration Ratios of Zinc Amalgams. Second Series {Cell II). 



*In amalgamating 0.005 gram of zinc was dissolved by ammonia; hence the amalgam 

 contained 1.1615 grams of zinc, or 0.8932 per cent. 



