Agricola, Georgius, De re metallica, 1912/1950

Page concordance

< >
Scan Original
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
< >
page |< < of 679 > >|
    <archimedes>
      <text>
        <body>
          <chap>
            <pb pagenum="247"/>
            <p type="main">
              <s>In assaying bismuth ore, place pieces of ore in the scorifier, and put
                <lb/>
              it under the muffle in a hot furnace; as soon as they are heated, they
                <lb/>
              drip with bismuth, which runs together into a button.</s>
            </p>
            <p type="main">
              <s>Quicksilver ore is usually tested by mixing one part of broken ore
                <lb/>
              with three-parts of charcoal dust and a handful of salt. </s>
              <s>Put the mixture into
                <lb/>
              a crucible or a pot or a jar, cover it with a lid, seal it with lute, place it on
                <lb/>
              glowing charcoal, and as soon as a burnt cinnabar colour shows in it, take
                <lb/>
              out the vessel; for if you continue the heat too long the mixture exhales the
                <lb/>
              quicksilver with the fumes. </s>
              <s>The quicksilver itself, when it has become cool, is
                <lb/>
              found in the bottom of the crucible or other vessel. </s>
              <s>Another way is to place
                <lb/>
              broken ore in a gourd-shaped earthen vessel, put it in the assay furnace,
                <lb/>
              and cover with an operculum which has a long spout; under the spout, put
                <lb/>
              an ampulla to receive the quicksilver which distills. </s>
              <s>Cold water should be
                <lb/>
              poured into the ampulla, so that the quicksilver which has been heated by the
                <lb/>
              fire may be continuously cooled and gathered together, for the quicksilver
                <lb/>
              is borne over by the force of the fire, and flows down through the spout of
                <lb/>
              the operculum into the ampulla. </s>
              <s>We also assay quicksilver ore in the very
                <lb/>
              same way in which we smelt it. </s>
              <s>This I will explain in its proper place.</s>
            </p>
            <p type="main">
              <s>Lastly, we assay iron ore in the forge of a blacksmith. </s>
              <s>Such ore is burned,
                <lb/>
              crushed, washed, and dried; a magnet is laid over the concentrates, and
                <lb/>
              the particles of iron are attracted to it; these are wiped off with a brush,
                <lb/>
              and are caught in a crucible, the magnet being continually passed over the
                <lb/>
              concentrates and the particles wiped off, so long as there remain any particles
                <lb/>
              which the magnet can attract to it. </s>
              <s>These particles are heated in the crucible
                <lb/>
              with saltpetre until they melt, and an iron button is melted out of them.
                <lb/>
              </s>
              <s>If the magnet easily and quickly attracts the particles to it, we infer that the
                <lb/>
              ore is rich in iron; if slowly, that it is poor; if it appears actually to repel
                <lb/>
              the ore, then it contains little or no iron. </s>
              <s>This is enough for the assaying of
                <lb/>
              ores.</s>
            </p>
            <p type="main">
              <s>I will now speak of the assaying of the metal alloys. </s>
              <s>This is done both
                <lb/>
              by coiners and merchants who buy and sell metal, and by miners, but most
                <lb/>
              of all by the owners and mine masters, and by the owners and masters of
                <lb/>
              the works in which the metals are smelted, or in which one metal is parted
                <lb/>
              from another.</s>
            </p>
            <p type="main">
              <s>First I will describe the way assays are usually made to ascertain what
                <lb/>
              portion of precious metal is contained in base metal. </s>
              <s>Gold and silver are
                <lb/>
              now reckoned as precious metals and all the others as base metals. </s>
              <s>Once
                <lb/>
              upon a time the base metals were burned up, in order that the precious metals
                <lb/>
              should be left pure; the Ancients even discovered by such burning what
                <lb/>
              portion of gold was contained in silver, and in this way all the silver was
                <lb/>
              consumed, which was no small loss. </s>
              <s>However, the famous mathematician,
                <lb/>
              Archimedes
                <emph type="sup"/>
              31
                <emph.end type="sup"/>
              , to gratify King Hiero, invented a method of testing the silver, </s>
            </p>
          </chap>
        </body>
      </text>
    </archimedes>
Impressum