358 PROCEEDINGS OP THE AMERICAN ACADEMY. 



undissociated complex may be calculated by simply multiplying the sup- 

 posed concentration C of the ionized part of the complex by , when 



a 



a is the degree of dissociation of the acid. The total concentration of the 



-i ri 



mercury present would then be C -f- C = -. But if the new 



ion has the formula HgCl 4 ", its concentration should be proportional to 



the square of the specific conductivity, k, according to our previous 



C k 2 



reasoning. That is to say, — =k — .* This equation is tested in the 



a a 



following table, by taking a value for the constant k which best satisfies 



the early part of the curve — namely 385. 



The bearing of these rather discrepant figures is best seen by plotting 



the results. The curve which depicts the relation of the quantity 



385 k 2 

 to the concentration of the hydrochloric acid is indicated by a 



dotted line in the diagram on page 351. While with great concentrations 

 it deviates considerably from the curve representing the amount of 

 mercuric chloride formed by hydrochloric acid, it is nevertheless of the 

 same general character. Considering the many uncertainties, including 



the doubt concerning the equation a = — , which interfere with its exact 



00 



determination, the agreement is indeed as close as one has a right to 

 expect. 



Corresponding curves, with about the same degree of agreement, may 

 be calculated for the other chlorides. It is perhaps worth while to call 

 attention to the fact that the amount of mercury found in the most dilute 

 solution studied, the tenth normal solution of sodic chloride, although very 

 small, is too great to correspond to the theoretical value. The excess of 

 about three milligrams per litre above the requirement of theory may 

 well be due to dissolved calomel, which possesses a slight but unknown 

 solubility of its own.f 



All these arguments, reinforcing the conclusions which Le Blanc and 

 Noyes reached from a different series of facts, seem to indicate that as 



*k — = k f - Tr because a = and k' = kA aa . Tlie more complex form is 



o \ A x 



retained because its meaning is the more obvious. 



t The work of Kohlrausch and Rose (Zeitschr. pliys. Cliem. 12, 241) is not con- 

 clusive concerning this solubility, since the behavior of calomel on solution is too 

 little known. Their results seemed to indicate that the solubility amounted to 

 three or four milligrams per litre. 



