OF THALLIUM, INDIUM, AND TIN 21 



hours later gave the values 25.231 and 25.243, in mean 25.237, exactly the 

 same as before. In subsequent work the agreements were of this order 

 of accuracy ; usually average values alone will be given. 



It is worthy of remark in this connection that the electrolyte was not 

 found to be the least alkaline to phenolphthalein after thus standing for 

 48 hours over a thallium amalgam. This fact is very satisfactory, not only 

 with regard to thallium, but also in its implication concerning the probable 

 integrity of amalgams of less easily oxidized metals, whose oxides are less 

 easily detected. 



It is interesting to compare the result with the ideal value calculated 

 from the gas law. The theoretical potential, calculated according to the 

 formula 



v = 8.3i6x (273.09) X2.3026 j c* 



96,530 Cn 



is 23.064 millivolts. This is 2.183 millivolts, or nearly 10 per cent, less 

 than the observed value 25.237. 



Having thus cleared the way by this preliminary work, four series of 

 more accurate measurements were made. Four multiple cells containing 

 thallium amalgam, designated A, B, C, and D, were prepared. In each 

 case an amalgam prepared electrolytically was placed in cup I ; and cups 

 2, 3, and 4 were filled with the same amalgam diluted (in an atmosphere of 

 hydrogen) with weighed amounts of mercury. 



The " parent amalgam " in cups Ai and Bi was made by depositing in 

 197.33 grams of mercury the amount of thallium equivalent to 0.4290 gram 

 of silver. This amalgam was diluted as follows: 



grams of amalgam. grams of mercury. 



13-272 + 82.933 in A2 



IS-679 4I-938 A3 



23.710 32.791 B2 



6.838 97.483 63 



11.736 83.642 64 



The " parent amalgam " in cup Ci was made by depositing in 168.361 

 grams of mercury the amount of thallium equivalent to 1.6738 grams of 

 silver. This amalgam was diluted as follows : 



grams of amalgam. grams of mercury. 



12.487 + 31.420 in C2 



10.710 75-495 C3 



10.448 112.095 4 



Finally the " parent amalgam " in cup Di was made by depositing in 

 213.65 grams of mercury the amount of thallium equivalent to 0.2289 

 grams of silver. This amalgam was diluted as follows : 



grams of amalgam. grams of mercury. 



14.967 + 29.589 in D2 



8.851 75-453 D3 



9.461 122.984 D4 



