A Gelatine Mould For Casting Plaster Ornaments
Allow twelve ounces of
Gelatine to soak for a few hours in water, until it has absorbed as
much as it can, then apply heat, by which it will liquify. If the mould
is required to be elastic, add three ounces of Treacle, and mix well
with the Gelatine. If a little Chrome Alum (precise proportions are
immaterial) be added to the Gelatine, it causes it to lose its property
of being again dissolved in water. A saturated solution of Bichromate
of Potash brushed over the surface of the mould, allowed to become dry
and afterwards exposed to sunlight for a few minutes, renders the
surface so hard as to be unaffected by moisture.