4 ENERGY CHANGES INVOLVED IN DILUTION OF AMALGAMS. 



deduced. It clearly establishes the priority of von Turin in announcing a 

 consistent theory for amalgam cells, although it is probable that G. Meyer 

 had already worked out much of it independently. 



In May, 1890, Meyer 10 published a research on " The electromotive forces 

 between glass and amalgams." Working at high temperatures the glass 

 behaved as an electrolyte, and he was able to measure cells of the type 



Mercury, Glass, Sodium amalgam. 

 By subtraction of the potentials of two cells containing amalgams of differ- 

 ent concentrations, he calculated the potential of several cells of the type 

 Sodium amalgam dilute, Glass, Sodium amalgam concentrated. 



He showed the process taking place in such an element to be reversible, and 

 pointed out that the electromotive force should be proportional to the abso- 

 lute temperature in case the heat of dilution was negligible. But his attempt 

 to apply the principles laid down by Helmholtz was incomplete, and, so far 

 as it went, discordant with his results. In a postscript to this article, how- 

 ever, he mentioned the article of von Turin, and stated that he had been for 

 two months past occupied in determining the molecular weights of zinc and 

 cadmium in mercury by a very similar method. These both corresponded 

 with their atomic weights, and further investigation was in progress. 



In November of the same year, von Turin, 11 in an address before the Rus- 

 sian Physico-Chemical Society, proved that his theoretical conclusions were 

 verified by the measurements of Lindeck. He showed that all the metals 

 investigated in that research were monatomic, and pointed out the bearing 

 of Ramsay's experiments u upon the question at issue. No review of this 

 address appeared in any German periodical at the time. In February, 1891, 

 von Turin 13 corrected and amplified his first paper, but said nothing about 

 the work of Lindeck. 



Three months later G. Meyer " published his well-known research on the 

 " Molecular weights of some metals," and reiterated his claim to priority in 

 confirming the theoretical formula by experiment. He then developed the 

 equation for zinc amalgam cells from a consideration of the osmotic work 

 involved in a reversible cycle a more direct treatment than von Turin's. 



In the formula E = 1.908 2- T log ^ , q represents the electrochemical 



m c 2 



equivalent, in grams, of the metal, and m the molecular weight of the metal 



10 Wied. Ann., 40, 244 (1890). 

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

 12 J. Chem. Soc, 55, 521 (1889). 

 13 Zeit. Phys. Chem., 7, 221 (1891). 

 "Ibid., 477 (1891). 



