The U. S. Pharmacopoeia directs this to be made by incorporating twenty grains of iodine and four of iodide of potassium with a troyounce of lard; the iodine and iodide being first rubbed with six minims of water. The use of the iodide is simply to facilitate the incorporation; and the preparation is strictly an ointment of iodine. it should be prepared as wanted, as it is changed by time.

This is used chiefly for friction over the surface of enlarged glands and other tumefactions, or to the insides of the legs and arms, with a view to the absorption of the iodine. it is apt, when often repeated, to irritate the surface, and cause a pustular eruption. The quantity to be used varies, with the extent of the surface of application, from a scruple to one or two drachms.