filth be therein, it is cleansed thereof. And that maketh the gold
more pure and shining. No metal stretcheth more with hammer work than
gold, for it stretcheth so, that between the anvil and the hammer
without breaking and rending in pieces it stretcheth to gold foil. And
among metals there is none fairer in sight than gold, and therefore
among painters gold is chief and fairest in sight, and so it
embellisheth colour and shape, and colour of other metals. Also among
metals is nothing so effectual in virtue as gold. Plato describeth the
virtue thereof and saith that it is more temperate and pure than other
metals. For it hath virtue to comfort and for to cleanse superfluities
gathered in bodies. And therefore it helpeth against leprosy and
meselry. The filings of gold taken in meat or in drink or in medicine,
preserve and let breeding of leperhood, or namely hideth it and maketh
it unknown.

Orpiment is a vein of the earth, or a manner of free stone that
cleaveth and breaketh, and it is like to gold in colour: and this is
called Arsenic by another name, and is double, red and citron. It hath
kind of brimstone, of burning and drying. And if it be laid to brass,
it maketh the brass white, and burneth and wasteth all bodies of
metal, out take gold.

Though silver be white yet it maketh black lines and strakes in the
body that is scored therewith. In composition thereof is quicksilver
and white brimstone, and therefore it is not so heavy as gold. There
are two manner of silvers, simple and compound. The simple is
fleeting, and is called quicksilver; the silver compounded is massy
and sad, and is compounded of quicksilver pure and clean, and of white
brimstone, not burning, as Aristotle saith.