636 
CHEMISTRY: LEWIS AND MINE 
The extraordinary difference between the three t3^es of amalgam is 
shown in figure 1, from which it will be seen that a small addition of 
potassium increases the resistance of mercury, an equivalent . amount 
of sodium produces a less increase in the resistance, while the addition 
of lithium diminishes the resistance. 
It might have been expected, at first sight at least, that in accord- 
ance with the theory of electrolytic dissociation the strongly electro- 
positive alkali metals would, owing to a greater dissociation, increase 
the conductivity of mercury. But when we consider the well substan- 
tiated fact that all these metals are, when dissolved in mercury, com- 
bined with the solvent to form hydrargyrates of greater or less com- 
plexity, the results cannot be considered to disprove this theory. Never- 
theless it is important to observe that in interpreting the conductivity 
and transference number of dilute amalgams, the generalizations which 
can be drawn and the analogies which suggest themselves are of a very 
different character from those which have been found useful in the 
interpretation of the phenomena of aqueous solutions. 
Thus in the paper of Lewis, Adams, and Lanman it has been shown 
that, contrary to expectation, the strongly electropositive metals so- 
dium and potassium, when dissolved in mercury, wander in the direc- 
tion not of the positive but of the negative current. They show further 
that this phenomenon is closely correlated with the increase in resist- 
ance produced in mercury by the solution of these metals; for if the in- 
