Agricola, Georgius, De re metallica, 1912/1950
page |< < of 679 > >|
    <archimedes>
      <text>
        <body>
          <chap>
            <p type="main">
              <s>
                <pb pagenum="252"/>
              silver, combined with a certain portion of lead, into the cupel, in which way
                <lb/>
              the assay is rendered erroneous. </s>
              <s>Then take the beads out of the cupel and
                <lb/>
              clean them of dross. </s>
              <s>If neither depresses the pan of the balance in which it
                <lb/>
              is placed, but their weight is equal, the assay has been free from error; but
                <lb/>
              if one bead depresses its pan, then there is an error, for which reason the
                <lb/>
              assay must be repeated. </s>
              <s>If the
                <emph type="italics"/>
              bes
                <emph.end type="italics"/>
              of coin contains but seven
                <emph type="italics"/>
              unciae
                <emph.end type="italics"/>
              of
                <lb/>
              pure silver it is because the King, or Prince, or the State who coins the money,
                <lb/>
              has taken one
                <emph type="italics"/>
              uncia,
                <emph.end type="italics"/>
              which he keeps partly for profit and partly for the
                <lb/>
              expense of coining, he having added copper to the silver. </s>
              <s>Of all these
                <lb/>
              matters I have written extensively in my book
                <emph type="italics"/>
              De Precio Metallorum et
                <lb/>
              Monetís.
                <emph.end type="italics"/>
              </s>
            </p>
            <p type="main">
              <s>We assay gold coins in various ways. </s>
              <s>If there is copper mixed with
                <lb/>
              the gold, we melt them by fire in the same way as silver coins; if there is
                <lb/>
              silver mixed with the gold, they are separated by the strongest
                <emph type="italics"/>
              aqua valens;
                <emph.end type="italics"/>
                <lb/>
              if there is copper and silver mixed with the gold, then in the first place, after
                <lb/>
              the addition of lead, they are heated in the cupel until the fire consumes the
                <lb/>
              copper and the lead, and afterward the gold is parted from the silver.</s>
            </p>
            <p type="main">
              <s>It remains to speak of the touchstone
                <emph type="sup"/>
              37
                <emph.end type="sup"/>
              with which gold and silver are
                <lb/>
              tested, and which was also used by the Ancients. </s>
              <s>For although the assay made
                <lb/>
              by fire is more certain, still, since we often have no furnace, nor muffle, nor
                <lb/>
              crucibles, or some delay must be occasioned in using them, we can always
                <lb/>
              rub gold or silver on the touchstone, which we can have in readiness.
                <lb/>
              </s>
              <s>Further, when gold coins are assayed in the fire, of what use are they after­
                <lb/>
              ward? </s>
              <s>A touchstone must be selected which is thoroughly black and free
                <lb/>
              of sulphur, for the blacker it is and the more devoid of sulphur, the better it </s>
            </p>
          </chap>
        </body>
      </text>
    </archimedes>
Impressum