g the connexion with the battery, the portions of asbestus
were lifted out, and the drops hanging at the ends allowed to fall each
into its respective vessel. The acids in _a_ and _b_ were then first
compared, for which purpose two evaporating dishes were balanced, and the
acid from _a_ put into one, and that from _b_ into the other; but as one
was a little heavier than the other, a small drop was transferred from the
heavier to the lighter, and the two rendered equal in weight. Being
neutralized by the addition of the soda solution (525.), that from _a_, or
the negative vessel, required 15 parts of the soda solution, and that from
_b_, or the positive vessel, required 16.3 parts. That the sum of these is
not 34 parts is principally due to the acid removed with the asbestus; but
taking the mean of 15.65 parts, it would appear that a twenty-fourth part
of the acid originally in the vessel _a_ had passed, through the influence
of the electric current, from _a_ into _b_.

528. In comparing the difference of acid in A and B, the necessary equality
of weight was considered as of no consequence, because the solution was at
first neutral, and would not, therefore, affect the test liquids, and all
the evolved acid would be in B, and the free alkali in A. The solution in A
required 3.2 measures of the prepared acid (525.) to neutralize it, and the
solution in B required also 3.2 measures of the soda solution (525.) to
neutralize it. As the asbestus must have removed a little acid and alkali
from the glasses, these quantities are by so much too small; and therefore
it would appear that about a tenth of the acid originally in the vessel A
had been transferred into B during the continuance of the electric action.

529. In another similar experiment, whilst a thirty-fifth part of the acid
passed from _a_ to _b_; in the free acid vessels, between a tenth and an
eleventh passed from A to B in the combined acid vessels. Other experiments
of the same kind gave similar results.

530. The variation of electro-chemical decomposition, the transfer of
elements and their accumulation at the poles, according as the substance
submitted to action consists of particles opposed more or less in their
chemical affinity, together with the consequent influence of the latter
circumstances, are sufficiently obvious in these cases, where sulphuric
acid is acted upon in the _same quantity_ by the _same_ electric current,
but in one case opposed to the com