Characters. - It has a fine lemon-yellow colour and a consistence like butter. It is apt to become decolourised when mixed with metals or deoxidising powders, and hence an excess of acid is used in order that it may reoxidise them as necessary. It should be spread with a wooden or ivory spatula.

Preparation. - By mixing a hot solution of mercury in nitric acid with lard and olive oil, B.P.; or with lard oil, U.S.P.

Uses. - This ointment was made in imitation of Singleton's golden eye-ointment, and it is of remarkable service in ophthalmia tarsi. It should be mixed with its own weight of almond oil and applied to the lids.

It is also applied to phagedenic ulcers and syphilitic sores, and soon destroys the parasitic fungi on which ringworm, etc, depend.

Preparation.

b.p.

Unguentum Hydrargryri Nitratis Dilutum (Nitrate of Mercury Ointment 1, Soft Paraffin 2).