Page 85 - My FlipBook

f 'SES Of HEA I 'Y GOLD.
7 1
it remains only to say that in such circumstances they should not be
used at all. The entire filling must be made with rolled gold, other-
wise known as heavy foil. This me to as a
brings good place as any
for explaining what I think the relative values of the three forms of
gold. The use of crystal I have told. I would depend upon pellets
for everything between the crystal and the last third of the filling,
which should invariably be made with heavy foil.
My reason for this is that experience has taught me that fillings
or made with
completed, throughout heavy foil, will retain their
surfaces much than
smooth, polished longer any made otherwise. I
have a theory to offer as a cause for this. If we take a of foil
strip
and roll it into a rope, there is necessarily air between the folds. If,
now, we cut this into pellets, with each snip of the scissors we com-
press the edges of a pellet, practically sealing within it several cells of
When with these, we
air. filling only compress the gold as much as
the contained air will permit. It will be claimed here that this is an
argument, first, against using such pellets at all, and secondly, in favor
of replacing them with the blocks or cylinders which I have con-
demned. My reply to the first would be that pellets of this kind, in
spite of the argument, will make a good gold filling, even used at the
surface, and where heavy gold is employed for the last third of the
serve all our To the second, while
filling, they certainly purpose.
admitting that the block or cylinder has the edges open, thus appear-
ing to offer an outlet for any contained air, they are nevertheless open
to the same objection, because to the air it would
exactly surely expel
be necessary in condensing to begin at one point and then work
exactly uniformly toward the edges of the pellet, or to start at one end
and approach the other, neither of which is done in
probably any
instance, and surely not with every block or cylinder. The heavy foil
is better because it is of a single thickness, and does not contain any
air at the start. Yet, even with this magnificent material, care must
be observed in the same direction, for if not properly attached and
condensed, air-cells will be produced.
I now come to a discussion of the merits and usefulness of
heavy
or rolled gold. It is procurable in various thicknesses, numbered 30,
40, 60, and 1 20. The last is an extremity to which we need rarely
if ever resort. Numbers 30 and 60 are sufficient for all purposes, and
we may practically produce the latter by folding the former once, be-
fore cutting.
The earlier advocates of this form of gold were so enthusiastic over
it that they claimed to depend upon it entirely. The theory was that
the more gold one could crowd into a cavity, the better the result.
This is not true. The supreme demand upon any filling is that it
shall a durable surface, and be in close contact with all its
present