which men stand divided one against the other, in their classes and
professions; the nobility and the third estate, for instance, or
soldiers and civilians."

"Then again," replied Edward, "as these are united under common laws and
customs, so there are intermediate members in our chemical world which
will combine elements that are mutually repulsive."

"Oil, for instance," said the Captain, "we make combine with water with
the help of alkalis----"

"Do not go on too fast with your lesson," said Charlotte. "Let me see
that I keep step with you. Are we not here arrived among the
affinities?"

"Exactly," replied the Captain; "we are on the point of apprehending
them in all their power and distinctness; such natures as, when they
come in contact, at once lay hold of each other, each mutually affecting
the other, we speak of as having an affinity one for the other. With the
alkalis and acids, for instance, the affinities are strikingly marked.
They are of opposite natures; very likely their being of opposite
natures is the secret of their inter-relational effect--each reaches out
eagerly for its companion, they lay hold of each other, modify each
other's character, and form in connection an entirely new substance.
There is lime, you remember, which shows the strongest inclination for
all sorts of acids--a distinct desire of combining with them. As soon as
our chemical chest arrives, we can show you a number of entertaining
experiments which will give you a clearer idea than words, and names,
and technical expressions."