POSOL′OGY. See Dose.
POS′SET. Syn. Possetum, L. Milk curdled with wine or any other slightly acidulous liquor. It is usually sweetened with either sugar or treacle, and is taken hot.
Prep. From new milk, 1⁄2 pint; sherry or marsala, 1 wine-glassful; treacle, 1 or 2 tablespoonfuls, or q. s.; heat them together in a clean saucepan until the milk coagulates. This is called ‘treacle posset’ or ‘molasses posset,’ and, taken on retiring to rest, is highly esteemed in some parts of the country as a domestic remedy for colds. Lemon juice, strong old ale, or even vinegar, is occasionally substituted for wine, and powdered ginger or nutmeg added at will.
POT METAL. See Cock metal.
POT′ASH. The ‘potash,’ or ‘potashes’ of commerce is an impure carbonate of potassium, so named after the pots or vessels in which it was first made. The ‘potash,’ or ‘potassa,’ of the chemist is the hydrate of a peculiar metal, potassium, which is more particularly referred to below. The word potash is vulgarly applied to the crude or commercial carbonate of potassium. See Carbonate of Potassium, &c.
Potash is now principally obtained from the following sources:—
1. From carnallite,[119] a hydrated double chloride of potassium and magnesium, which occurs associated with other salts of potassium
and magnesium, as well as of sodium, in a bed of clay, at Stassfurth, near Madgeburg, in Prussia.
[119] Carnallite contains nearly a fourth of its weight of potassium chloride.
2. Feldspar and similar minerals.