The purified fat of the Hog, Sus scrofa.

Characters and tests.-A soft white fatty substance, melting at about 100°. Has no rancid odour. Dissolves entirely in ether.

Impurities.-Common salt and starch.

Composition.-Lard consists of 60 per-cent. of olein, and some palmitin and stearin. Olein is a fluid oil, a compound of oleic acid, C18H33C2, and glyceryl, C3H5. Palmitin and stearin are solid oils, compounds of glyceryl with palmitic acid (C16H32O2), and stearic acid (C18H36O2) respectively.

Preparations.

1. Adeps Benzoatus

Adeps Benzoatus. 1 of Benzoin in 64 of Lard.

2. Unguentum Simplex

Unguentum Simplex. 3 in 8, with White Wax and Almond Oil. Hither Lard or Benzoated Lard is contained in almost all ointments.

Action And Uses

Lard is a simple emollient, forming the basis of most of the officinal ointments. Benzoated lard does not become rancid like ordinary lard, which for the same reason is now in a measure replaced by vaseline.