in that case placed as a pavement of bricks.

When it is thought that the mercury has attracted all the silver,
the assayer takes a small quantity of ore from each cuerpo, which he
washes separately in a small earthen plate or wooden bowl; and, by the
colour and appearance of the amalgama found at the bottom, when the
earthy matters are washed away, he knows whether the mercury has
produced its proper effect. When blackish, the ore is said to have
been too much heated, and they add more salt, or some other temper. In
this case they say that mercury is _dispara_, that is, shoots or flees
away. If the mercury remains white, they put a drop under the thumb,
and pressing it hastily, the silver in the amalgam sticks to the
thumb, and the mercury slips away in little drops. When they conceive
that all the silver has incorporated with the mercury, the mixed mass,
or cuerpo, is carried to a basin or pond, into which a small stream
of water is introduced to wash it, much in the same way as I shall
afterwards describe the manner in which they wash gold, only that as
the silver-ore is reduced to a fine mud without stones, it is stirred
by an Indian with his feet, to dissolve it thoroughly, and loosen the
silver. From the first basin it falls into a second, and thence into
a third, where the stirring and washing is repeated, that any amalgam
which has not subsided in the first and second may not escape the
third.

The whole being thoroughly washed in these basins, which are lined
with leather, till the water runs clear off, the amalgam of mercury
and silver is found at the bottom, and is termed _la pella_. This is
put into a woollen bag and hung up, from whence some of the mercury
runs out. The bag is then beaten and pressed as much as they can,
laying upon it a flat piece of wood loaded with a heavy weight, to get
out as much of the mercury as they can. The paste is then put into
a mould of wooden planks bound together, generally in the form of an
octagon pyramid cut short, its bottoms being a plate of copper, full
of small holes, into which the paste is stirred and pressed down, in
order to fasten it. When they design to make many _pinnas_, or spongy
lumps of various weights, these are divided from each other by thin
beds or layers of earth, which hinder them from uniting. For this
purpose, the _pella_, or mass of amalgam, must be weighed out in
separate portions, deducting two-thirds for the contained mercury, by
which they kn