Agricola, Georgius, De re metallica, 1912/1950

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    <archimedes>
      <text>
        <body>
          <chap>
            <p type="main">
              <s>
                <pb pagenum="237"/>
              of this powder there are mixed two
                <emph type="italics"/>
              unciae
                <emph.end type="italics"/>
              of yellow litharge, likewise crushed.
                <lb/>
              </s>
              <s>This mixture is put into a scorifier large enough to hold it, and placed under
                <lb/>
              the muffle of a hot furnace; when the charge flows like water, which occurs
                <lb/>
              after half an hour, it is taken out of the furnace and poured on to a stone,
                <lb/>
              and when it has hardened it has the appearance of glass, and this is likewise
                <lb/>
              crushed. </s>
              <s>This powder is sprinkled over any metalliferous ore which does
                <lb/>
              not easily melt when we are assaying it, and it causes the slag to exude.</s>
            </p>
            <p type="main">
              <s>Others, in place of litharge, substitute lead ash,
                <emph type="sup"/>
              22
                <emph.end type="sup"/>
              which is made in the
                <lb/>
              following way: sulphur is thrown into lead which has been melted in a
                <lb/>
              crucible, and it soon becomes covered with a sort of scum; when this is
                <lb/>
              removed, sulphur is again thrown in, and the skin which forms is again taken
                <lb/>
              off; this is frequently repeated, in fact until all the lead is turned into
                <lb/>
              powder. </s>
              <s>There is a powerful flux compound which is made from one
                <emph type="italics"/>
              uncía
                <emph.end type="italics"/>
                <lb/>
              each of prepared saltpetre, melted salt, glass-gall, and argol, and one-third
                <lb/>
              of an
                <emph type="italics"/>
              uncia
                <emph.end type="italics"/>
              of litharge and a
                <emph type="italics"/>
              bes
                <emph.end type="italics"/>
              of glass ground to powder; this flux, being
                <lb/>
              added to an equal weight of ore, liquefies it. </s>
              <s>A more powerful flux is made by
                <lb/>
              placing together in a pot, smeared on the inside with litharge, equal portions
                <lb/>
              of white argol, common salt, and prepared saltpetre, and these are heated
                <lb/>
              until a white powder is obtained from them, and this is mixed with as much
                <lb/>
              litharge; one part of this compound is mixed with two parts of the ore which
                <lb/>
              is to be assayed. </s>
              <s>A still more powerful flux than this is made out of ashes
                <lb/>
              of black lead, saltpetre, orpiment,
                <emph type="italics"/>
              stíbíum,
                <emph.end type="italics"/>
              and dried lees of the
                <emph type="italics"/>
              aqua
                <emph.end type="italics"/>
              with
                <lb/>
              which gold workers separate gold from silver. </s>
              <s>The ashes of lead
                <emph type="sup"/>
              23
                <emph.end type="sup"/>
              are made from
                <lb/>
              one pound of lead and one pound of sulphur; the lead is flattened out into
                <lb/>
              sheets by pounding with a hammer, and placed alternately with sulphur in a
                <lb/>
              crucible or pot, and they are heated together until the fire consumes the
                <lb/>
              sulphur and the lead turns to ashes. </s>
              <s>One
                <emph type="italics"/>
              líbra
                <emph.end type="italics"/>
              of crushed saltpetre is mixed
                <lb/>
              with one
                <emph type="italics"/>
              libra
                <emph.end type="italics"/>
              of orpiment similarly ground to powder, and the two are cooked
                <lb/>
              in an iron pan until they liquefy; they are then poured out, and after cool­
                <lb/>
              ing are again ground to powder. </s>
              <s>A
                <emph type="italics"/>
              líbra
                <emph.end type="italics"/>
              of
                <emph type="italics"/>
              stíbíum
                <emph.end type="italics"/>
              and a
                <emph type="italics"/>
              bes
                <emph.end type="italics"/>
              of the
                <lb/>
              dried lees (
                <emph type="italics"/>
              of what?
                <emph.end type="italics"/>
              ) are placed alternately in a crucible and heated to the
                <lb/>
              point at which they form a button, which is similarly reduced to powder.
                <lb/>
              </s>
              <s>A
                <emph type="italics"/>
              bes
                <emph.end type="italics"/>
              of this powder and one
                <emph type="italics"/>
              líbra
                <emph.end type="italics"/>
              of the ashes of lead, as well as a
                <emph type="italics"/>
              líbra
                <emph.end type="italics"/>
              of
                <lb/>
              powder made out of the saltpetre and orpiment, are mixed together and a
                <lb/>
              </s>
            </p>
          </chap>
        </body>
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    </archimedes>
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