DOI Page / Citation link:
https://doi.org/10.11588/diglit.19574#0360
33° F E R
mixture and lay it all over the cieling very fmooth ; carve thert
on it what you pleafe, or lay to it fome ornament with moulds,
which are cut in fmooth wood or caft in lead; fill the mould
with the mixture, prefs it to the cieling, and it will ftick and
come clean out of the mould ; let it dry ; when dry, and you
perceive that it is not every-where of a good white, then, with
a clean pencil, brufh, and clear water, ftrike it over, and it
whitens ofitfelf. It will, in time, grow as hard as (tone.
To make FERETTO of Spain ffor tinging of glafs. The name
Feretto comes from the Italian and Spanifh, and is fo called be-
caufe it is found in iron mines ; and commonly Feretto of Spain,
becaufe the moft part of what was fold in other parts of Europe,
and which was the beft, was found in thofe mines, and comes to
us from thence.
There is fome of it black, like iron, and which communicates
its colour to the matter, in which it is ufed, which is the reafon
it ought to be chofenj for good Feretto is known by its being
red ; and, being beaten, imitates the colour of cinnabar, which
it always does, when it is pretty well calcined.
Pomet, in his hiftory of drugs, fays, that the lapis haematites
is what we commonly call the Feretto of Spain ; that this mine-
ral is of a reddifh colour, hard, weighty, and pointed with long
and (harp points; that it is brought from feveral places, foraf-
much as there are no iron mines in which it is not found.
That the name haematites is given it of haima, which figni-
lies blood, becaufe this ftone is good for (lopping of blood ; and
it is called the blood-ftone, becaufe it is of the colour of blood ;
and Feretto, becaufe it is found in iron mines.
Although Feretto be found in mines, yet it may be artificially
made much better.
Excellent Feretto ufed to be made anciently in Cyprus, and
at Memphis, the metropolis of Egypt; but it is not now in ufe,
as formerly.
Neri and Merret, who have written of the art of glafs, ufe
only copper or brafs for making of Feretto ; but true Feretto
cannot be made without iron or fteel.
An ordinary way of making Feretto is this. Take filings
of iron very clean, and fulphur beat to powder; put them in a
crucible, layer over layer, or firft one layer of fulphur, then one
of filings, and fo on; beginning and ending with the fulphur,
which is called ftratification, or ftratum fuper firatum. Cover
the crucible with another, or with a tile, and lute it clofe, and
fet it into a furnace with coals round it for fix hours, increafing
the fire every two hours ; that is, for the two firft hours, let the
fire or coals be half a foot from the crucible, the two fecond
abquj;
mixture and lay it all over the cieling very fmooth ; carve thert
on it what you pleafe, or lay to it fome ornament with moulds,
which are cut in fmooth wood or caft in lead; fill the mould
with the mixture, prefs it to the cieling, and it will ftick and
come clean out of the mould ; let it dry ; when dry, and you
perceive that it is not every-where of a good white, then, with
a clean pencil, brufh, and clear water, ftrike it over, and it
whitens ofitfelf. It will, in time, grow as hard as (tone.
To make FERETTO of Spain ffor tinging of glafs. The name
Feretto comes from the Italian and Spanifh, and is fo called be-
caufe it is found in iron mines ; and commonly Feretto of Spain,
becaufe the moft part of what was fold in other parts of Europe,
and which was the beft, was found in thofe mines, and comes to
us from thence.
There is fome of it black, like iron, and which communicates
its colour to the matter, in which it is ufed, which is the reafon
it ought to be chofenj for good Feretto is known by its being
red ; and, being beaten, imitates the colour of cinnabar, which
it always does, when it is pretty well calcined.
Pomet, in his hiftory of drugs, fays, that the lapis haematites
is what we commonly call the Feretto of Spain ; that this mine-
ral is of a reddifh colour, hard, weighty, and pointed with long
and (harp points; that it is brought from feveral places, foraf-
much as there are no iron mines in which it is not found.
That the name haematites is given it of haima, which figni-
lies blood, becaufe this ftone is good for (lopping of blood ; and
it is called the blood-ftone, becaufe it is of the colour of blood ;
and Feretto, becaufe it is found in iron mines.
Although Feretto be found in mines, yet it may be artificially
made much better.
Excellent Feretto ufed to be made anciently in Cyprus, and
at Memphis, the metropolis of Egypt; but it is not now in ufe,
as formerly.
Neri and Merret, who have written of the art of glafs, ufe
only copper or brafs for making of Feretto ; but true Feretto
cannot be made without iron or fteel.
An ordinary way of making Feretto is this. Take filings
of iron very clean, and fulphur beat to powder; put them in a
crucible, layer over layer, or firft one layer of fulphur, then one
of filings, and fo on; beginning and ending with the fulphur,
which is called ftratification, or ftratum fuper firatum. Cover
the crucible with another, or with a tile, and lute it clofe, and
fet it into a furnace with coals round it for fix hours, increafing
the fire every two hours ; that is, for the two firft hours, let the
fire or coals be half a foot from the crucible, the two fecond
abquj;