|
BOOK X
|
221
|
||
|
|
|||
|
make a sound when the stone is shaken, for example, the callimus in
geodes. In some places the stones adhere to the interior of the geode
and make no sound when shaken. A stone may contain many stones such as
the gems in the round Motschean geodes that are soft, of many species,
and adhering to the Avails. The Megarian conchites stone contains many shells.
Even
though a compound substance contains an abundance of metal, any earth,
congealed juice, or stone adhering to it will change the composition.
So much concerning compound substances that consist of two simple
natural substances.
I
shall now discuss compound substances containing two mixed substances.
Any of the six genera of mixed substances may be combined with any
other. There are just as many species of these genera of compound
substances as there are different compositions. For example, if the
compound contains a species of the first mixed genus, a sulphurous,
bituminous, or some other species, the addition of any species of any
of the other five genera will change the composition. If the compound
substance contains, in abundance, the first genus and species of the
second genus are added to it a great variety of compounds are possible,
since, in the second genus we have mixed auriferous stones, two species
of argentiferous and three species of plumbiferous, cupriferous and
ferruginous stones. Each species, as if a genus, embraces many other
species. For example, argentiferous stones include the silver minerals
that are gray, lead-gray, red, black, white, yellow, liver-colored, and
the color of pumice. Any one of these may adhere to a sulphurous stone.
Likewise particles of the species of the third to fifth genera may
adhere to species of the first genus and produce a great many different
compounds. There are as many if not more species in these other genera
than in the first genus although they are all known by the same name
with the exception of galena, pyrite, cadmia, and stibnite that
belong to the fifth genus. Finally, if particles of species of the
sixth genus are added to species of the first genus they will change
the composition. For example, atramentiferous pyrite may combine with
an atramentiferous stone. Thus numerous compound substances may be
produced by combining species of the second to sixth genera with other
species of any of these genera.
I
shall now discuss compound substances containing a simple and a mixed
substance. First, an earth may contain a particle of one of the species
of the first mixed genus or the particle may adhere to it. A
sulphurous, bituminous, or some other such stone will change the
composition of an earth. The same is true of combinations of the other
genera. I shall discuss species of the second genus since these are
known by the same names as those of the other genera and also because
more metal is recovered from them than from the species of the other
genera. Although metal is recovered from the latter species, for the
sake of brevity I shall not discuss them. An earth may embrace a mixed
auriferous, two species
|
|||
|
|
|||