HISTORICAL INTRODUCTION. 5 



in the amalgam. The electromotive force between dilute amalgams of zinc, 

 cadmium, lead, tin, copper, and sodium were measured with a fair degree 

 of accuracy. The conclusion that these metals, including sodium, were 

 monatomic in mercurial solution appeared well founded. Referring to Ram- 

 say's work on sodium, he speaks of his own failure to confirm it at the low 

 temperature prevailing in his research. 



Von Turin, 15 in commenting upon Meyer's paper, called attention to his 

 address before the Russian Society, but he still failed to mention Meyer's 

 preliminary announcement in Wiedemann's Annalen. 



His oversight in this respect may account for his ill-founded claim to 

 precedence in the experimental as well as the theoretical development of the 

 subject. 



The relation of the special equations of von Turin and Meyer to the general 



equation of Nernst, E = = In , is sufficiently evident without further 



\>r p 



comment. 



Seven years of inactivity in this line of investigation followed, and the 

 reason for the discrepancy between Meyer's and Ramsay's results on sodium 

 were still unexplained. 



In 1898 Schoellers 16 prepared various amalgams of sodium and barium 

 electrolytically, compared them with normal electrodes, and determined their 

 concentration analytically. From a pair of such measurements, on either 

 metal, the electromotive force of the corresponding amalgam cell could be 

 found by subtraction. This in each case agreed well with the potential de- 

 manded by the logarithmic formula, on the assumption sodium and barium 

 were monatomic. This research, however, was crude and left the question 

 at issue still unsettled. 



In October, 1898, Richards and Lewis presented to the American Academy 

 their research on zinc and cadmium amalgams. Accurate determinations of 

 electromotive force showed that zinc amalgams so concentrated as 1 per 

 cent, and cadmium amalgams of 3 per cent obeyed the laws of dilute solu- 

 tions with considerable fidelity. Neither the concentration of the electro- 

 lyte nor the nature of its anion had any influence upon the results, and the 

 potentials were strictly proportional to absolute temperature. The second 

 and third of these points, though inferred from the derivation of the formula, 

 had not previously been verified by experiment. More important still was 



Zeit. Phys. Chem., 8, 141 (1891). 

 'Chem. Cent. Blatt, 70, I, 16 (1899); Zeitschr. Electrochem., 5, 259 (1899). 



