ng sleep; which
shews that a greater quantity has been secreted, and that more of the
aqueous and saline part has been reabsorbed, and the earthy part left in
the bladder; hence thick urine in fevers shews only a greater action of the
vessels which secrete it in the kidneys, and of those which absorb it from
the bladder.

The same happens to the mucus expectorated in coughs, which is thus
thickened by absorption of its aqueous and saline parts; and the same of
the feces of the intestines. From hence it appears, and from what has been
said in No. 15. of this Section concerning the increase of irritability and
of sensibility during sleep, that the secretions are in general rather
increased than diminished during these hours of our existence; and it is
probable that nutrition is almost entirely performed in sleep; and that
young animals grow more at this time than in their waking hours, as young
plants have long since been observed to grow more in the night, which is
their time of sleep.

17. Two other remarkable circumstances of our dreaming ideas are their
inconsistency, and the total absence of surprise. Thus we seem to be
present at more extraordinary metamorphoses of animals or trees, than are
to be met with in the fables of antiquity; and appear to be transported
from place to place, which seas divide, as quickly as the changes of
scenery are performed in a play-house; and yet are not sensible of their
inconsistency, nor in the least degree affected with surprise.

We must consider this circumstance more minutely. In our waking trains of
ideas, those that are inconsistent with the usual order of nature, so
rarely have occurred to us, that their connexion is the slightest of all
others: hence, when a consistent train of ideas is exhausted, we attend to
the external stimuli, that usually surround us, rather than to any
inconsistent idea, which might otherwise present itself; and if an
inconsistent idea should intrude itself, we immediately compare it with the
preceding one, and voluntarily reject the train it would introduce; this
appears further in the Section on Reverie, in which state of the mind
external stimuli are not attended to, and yet the streams of ideas are kept
consistent by the efforts of volition. But as our faculty of volition is
suspended, and all external stimuli are excluded in sleep, this slighter
connexion of ideas takes place; and the train is said to be inconsistent;
that is, dissimilar to the