, by mere chance? Could
he imagine that he had clearly explained and accounted for such
industrious and skilful operation by talking of the nature and
instinct of a watch that should exactly show the hour to his master,
and slip away from such as should go about to break its springs to
pieces?

SECT. XXIV. Of Food.

What is more noble than a machine which continually repairs and
renews itself? The animal, stinted to his own strength, is soon
tired and exhausted by labour; but the more he takes pains, the more
he finds himself pressed to make himself amends for his labour, by
more plentiful feeding. Aliments daily restore the strength he had
lost. He puts into his body another substance that becomes his own,
by a kind of metamorphosis. At first it is pounded, and being
changed into a liquor, it purifies, as if it were strained through a
sieve, in order to separate anything that is gross from it;
afterwards it arrives at the centre, or focus of the spirits, where
it is subtilised, and becomes blood. And running at last, and
penetrating through numberless vessels to moisten all the members,
it filtrates in the flesh, and becomes itself flesh. So many
aliments, and liquors of various colours, are then no more than one
and the same flesh; and food which was but an inanimate body
preserves the life of the animal, and becomes part of the animal
himself; the other parts of which he was composed being exhaled by
an insensible and continual transpiration. The matter which, for
instance, was four years ago such a horse, is now but air, or dung.
What was then either hay, or oats, is become that same horse, so
fiery and vigorous--at least, he is accounted the same horse,
notwithstanding this insensible change of his substance.

SECT. XXV. Of Sleep.

The natural attendant of food is sleep; in which the animal forbears
not only all his outward motions, but also all the principal inward
operations which might too much stir and dissipate the spirits. He
only retains respiration, and digestion; so that all motions that
might wear out his strength are suspended, and all such as are
proper to recruit and renew it go on freely of themselves. This
repose, which is a kind of enchantment, returns every night, while
darkness interrupts and hinders labour. Now, who is it that
contrived such a suspension? Who is it that so well chose the
operations that ought to continue; and, with so just discernment,
excluded all