any distortion
by too violent compression--and continue the plaster as far as the
lower border of the chin; cover that part of the chest and arms that
is to be represented, and carry the plaster upwards, so as to join the
cast of the face; then carefully remove each, and season for casting,
by soaking or brushing with linseed oil boiled with sugar of lead or
licharge. Some persons boil the moulds in the oil; and many, instead
of casting the face in one piece, and the chest in another, lay
threads across the face and up and down it, leaving the ends out. As
the plaster sets, or is nearly set, the threads are pulled through, so
as to divide the cast into four, five, or more pieces.

2378. Procedure (3).

The back part of the head is moulded by having an oval trencher sort
of vessel, deeper than half the head, and generally made of plaster,
and boiled in oil. The back of the head being oiled, and this trencher
partially filled with liquid plaster of Paris, the head is lowered
into it, and the cast taken. The back of the neck is cast with the
person turned over on his face.

2379. Procedure (4).

Each part of the mould is marked so as to secure accurate junction
with the adjoining part or parts; sometimes with a x or ||, which,
passing over the junction of two pieces, serves to distinguish them.

2380. Procedure (5).

To model the face, join the several pieces, and tie them together with
twine; then wrap some rag round the joints, to prevent the plaster
oozing out, and pour in the plaster, made tolerably fluid, taking care
to oil the inside of the mould very carefully first. When the outer
part of the mould is nearly set, scoop out the centre with a spoon,
and let the whole dry; then remove the strings, &c., and smooth off
the edges of the joints upon the model with a sharp penknife, and
carve out the eyes from the mass, otherwise they will appear as if
closed.

2381. Wax Models.

Wax models may be made from the moulds used for the plaster; but when
the wax sets at the outside to about one-eighth of an inch, the rest
should be poured out of the mould; or, a smaller portion being poured
in, it may be shaken about the inside of the mould until it is coated.
The pieces are removed, and the seams trimmed up, as in the plaster
cast.

2382. Making a Cast.

If a cast be made in Gutta Percha from the model in plaster--or, what
is still