OF ZINC, CADMIUM, LEAD, COPPER, AND LITHIUM 



59 



12.762 grams of mercury) gave a potential of 0.009405 volt at 23.03, and 

 must have had a value for the function ^,=o.oo3655. 48 



'7T f *L\ I 



From these facts the following results may be calculated : 

 R , c, 8.; 



=0.0000303 



I7r 



= 0.00365571-0 = 0.003655(^3 -23 ^j ....=0.0000318 

 Difference =0.0000015 



Thus the discrepancy, which (according to the previous method of cal- 

 culation, already explained in the case of zinc) had seemed very large 

 when heaped upon the smallest term, does not exceed 5 per cent when 

 applied to the larger terms. 



Thus all the six metals, thallium, indium, tin, lead, zinc, and cadmium, 

 show an approximate agreement with the Cady equation, when tested in 

 this way. The discrepancy never exceeds 5 per cent, and usually is little 

 greater than 2 per cent. The deviations are sometimes in one direction, 

 and sometimes in another, and in some cases are no greater than the errors 

 of experimentation. For the sake of convenient reference, it is worth 

 while to present in a single table all these results concerning the equation 



ATT 



AT vF. 



Although by no means giving all the results which may be calculated 

 from the measurements, table 17 presents a typical example of each metal, 

 as well as of the effect of increasing dilution. 



TABLE 17. The Application of the Equation Derived from that of Cady. 



The theoretical significance of the close agreements shown in this table 

 is worth further attention. 



49 Carnegie Institution of Washington, Publication No. 56, p. 50. 



