s,
the diffusion does bring about a separation of the ions. Thus the
argument is turned round, and the proof supposed to be given of the
incorrectness of the theory becomes a further reason in its favour.

It is possible, no doubt, to adduce a few other experiments which are
not very favourable to M. Arrhenius's point of view, but they are
isolated cases; and, on the whole, his theory has enabled many
isolated facts, till then scattered, to be co-ordinated, and has
allowed very varied phenomena to be linked together. It has also
suggested--and, moreover, still daily suggests--researches of the
highest order.

In the first place, the theory of Arrhenius explains electrolysis very
simply. The ions which, so to speak, wander about haphazard, and are
uniformly distributed throughout the liquid, steer a regular course as
soon as we dip in the trough containing the electrolyte the two
electrodes connected with the poles of the dynamo or generator of
electricity. Then the charged positive ions travel in the direction of
the electromotive force and the negative ions in the opposite
direction. On reaching the electrodes they yield up to them the
charges they carry, and thus pass from the state of ion into that of
ordinary atom. Moreover, for the solution to remain in equilibrium,
the vanished ions must be immediately replaced by others, and thus the
state of ionisation of the electrolyte remains constant and its
conductivity persists.

All the peculiarities of electrolysis are capable of interpretation:
the phenomena of the transport of ions, the fine experiments of M.
Bouty, those of Professor Kohlrausch and of Professor Ostwald on
various points in electrolytic conduction, all support the theory. The
verifications of it can even be quantitative, and we can foresee
numerical relations between conductivity and other phenomena. The
measurement of the conductivity permits the number of molecules
dissociated in a given solution to be calculated, and the number is
thus found to be precisely the same as that arrived at if it is wished
to remove the disagreement between reality and the anticipations which
result from the theory of Professor Van t' Hoff. The laws of
cryoscopy, of tonometry, and of osmosis thus again become strict, and
no exception to them remains.

If the dissociation of salts is a reality and is complete in a dilute
solution, any of the properties of a saline solution whatever should
be represented numerically a