The gold should fall out
cleanly and completely on merely inverting the cup over the pan of the
balance. The flask and cup are then inverted so that the flask stands
mouth down in the cup; a little of the water from the flask flows into
the cup, but only a little. The gold falls steadily through the water
into the cup. When time has been allowed for even the finest of the gold
to have settled into the cup, the flask is removed. This is easiest done
under water. The cup, with the flask still resting in it, is dipped
under water in a basin; as soon as the neck of the flask is immersed the
crucible can safely be drawn away from under it and then lifted out of
the water. The flask should not be taken away first, for the rush of
water from it may easily sweep the gold out of the cup. The water in the
cup is then drained off and the cup is dried at not too high a
temperature; for if the last drop or two of water should boil there is
danger of spattering the gold out of the crucible. When it is dry, the
cup is heated on a pipe-clay triangle over a Bunsen burner, or on a slab
of asbestos in a muffle, to a dull-red heat. This brings the gold to
"colour"; that is, the loose tender dark coloured gold becomes bright
yellow and coherent; and is in a state fit to be transferred to the
balance and weighed. All unnecessary transferences must be avoided.
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