liquid kind is composed of the small and unequal particles
of water; and moves itself and is moved by other bodies owing to the
want of uniformity and the shape of its particles; whereas the fusile
kind, being formed of large and uniform particles, is more stable than
the other, and is heavy and compact by reason of its uniformity.
But when fire gets in and dissolves the particles and destroys the
uniformity, it has greater mobility, and becoming fluid is thrust forth
by the neighbouring air and spreads upon the earth; and this dissolution
of the solid masses is called melting, and their spreading out upon the
earth flowing. Again, when the fire goes out of the fusile substance, it
does not pass into a vacuum, but into the neighbouring air; and the air
which is displaced forces together the liquid and still moveable mass
into the place which was occupied by the fire, and unites it with
itself. Thus compressed the mass resumes its equability, and is again
at unity with itself, because the fire which was the author of the
inequality has retreated; and this departure of the fire is called
cooling, and the coming together which follows upon it is termed
congealment. Of all the kinds termed fusile, that which is the densest
and is formed out of the finest and most uniform parts is that most
precious possession called gold, which is hardened by filtration through
rock; this is unique in kind, and has both a glittering and a yellow
colour. A shoot of gold, which is so dense as to be very hard, and takes
a black colour, is termed adamant. There is also another kind which has
parts nearly like gold, and of which there are several species; it is
denser than gold, and it contains a small and fine portion of earth, and
is therefore harder, yet also lighter because of the great interstices
which it has within itself; and this substance, which is one of the
bright and denser kinds of water, when solidified is called copper.
There is an alloy of earth mingled with it, which, when the two parts
grow old and are disunited, shows itself separately and is called rust.
The remaining phenomena of the same kind there will be no difficulty in
reasoning out by the method of probabilities. A man may sometimes set
aside meditations about eternal things, and for recreation turn to
consider the truths of generation which are probable only; he will thus
gain a pleasure not to be repented of, and secure for himself while
he lives a wise and moderate p