little powder is again moistened, and thrown into the test, and tamped ; this
work is repeated until the test is entirely full of the powder, which the
master then cuts out with a knife, sharp on both sides, and turned upward at
both ends so that the central part is a palm and a digit long ; therefore it is
partly straight and partly curved. The blade is one and a half digits wide,
and at each end it turns upward two palms, which ends to the depth of a
palm are either not sharpened or they are enclosed in wooden handles. The
master holds the knife with one hand and cuts out the powder from the test,
so that it is left three digits thick all round ; then he sifts the powder of dried
bones over it through a sieve, the bottom of which is made of closely-woven
bristles. Afterward a ball made of very hard wood, six digits in diameter,
is placed in the test and rolled about with both hands, in order to make the
inside even and smooth ; for that matter he may move the ball about with only
one hand. The tests40 are of various capacities, for some of them when prepared
40The refining of silver in " tests " (Latin testa) is merely a second cupellation, with
greater care and under stronger blast. Stirring the mass with an iron rod serves to raise the
impurities which either volatilize as litharge or, floating to the edges, are absorbed into the
" test." The capacity of the tests, from 15 librae to 50 librae, would be from about 155 to
515 ozs. Troy.
