Unguentum it is one of the most effectual alterative applications in old and obstinate skin diseases; and is peculiarly adapted to psoriasis, lepra, pityriasis, and porrigo, and to the very advanced stage of impetigo and eczema.

Sulphuris iodidi. U. S.

This ointment is made by simply incorporating iodide of sulphur with lard, in the proportion of half a drachm of the former to an ounce of the latter. The iodide of sulphur is procured by fusing a mixture of sulphur and iodine.

* Dr. R. S. Sisson communicates to the London Lancet (April, 1860, p. 382) the following account of his own experience. Beginning with 2 grains twice daily, and increasing by 1 grain every third day, he reached the daily dose of 100 grains; then, intermitting for two weeks, and resuming with 10 grains daily, which was increased by 5 grains every third day, he persevered until the quantity taken in twenty-four hours was one ounce; and from all this quantity he experienced no other effect than slight catarrhal symptoms. (Note to the third edition.) vol. II.-24 it was first proposed as a medicine by Dr. A. Buchanan, of Glasgow, who prepared it by rubbing twenty-four grains of iodine with a little water, and then with an ounce of fine starch gradually added, and continuing the process until the powder assumed a uniform blue colour. it was then dried by a moderate heat, and kept in well-stopped bottles. He gave a heaped teaspoonful, mixed with water-gruel, three times a day, and increased the dose, if deemed desirable, to a tablespoonful. He gave even an ounce without unpleasant effect; as the compound produces little or no irritation of stomach or bowels. it is peculiarly indicated, whenever the object is to introduce as much iodine as possible into the system, without risk of injury to the stomach.* in general it should not be given with substances with which iodine itself is incompatible.