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OF TAKING CASTS OF MEDALS.
A paste of emery mixed with aqua vitae, or iron filings with
vinegar, or ashes of walnut leaves, or ashes of straw very finely
powdered.
[Footnote: The meaning of scagliuolo in this passage is doubtful.]
The diameter is given in the lead enclosed; it is beaten with a
hammer and several times extended; the lead is folded and kept
wrapped up in parchment so that the powder may not be spilt; then
melt the lead, and the powder will be on the top of the melted lead,
which must then be rubbed between two plates of steel till it is
thoroughly pulverised; then wash it with aqua fortis, and the
blackness of the iron will be dissolved leaving the powder clean.
Emery in large grains may be broken by putting it on a cloth many
times doubled, and hit it sideways with the hammer, when it will
break up; then mix it little by little and it can be founded with
ease; but if you hold it on the anvil you will never break it, when
it is large.
Any one who grinds smalt should do it on plates of tempered steel
with a cone shaped grinder; then put it in aqua fortis, which melts
away the steel that may have been worked up and mixed with the
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