Mercury ointments in various forms have long been a standby for the dermatologist. First, metallic mercury ointments were employed, and in recent times the ammoniated mercury ointment has enjoyed tremendous vogue. In the last few years, calomel ointment has been used in the so-called clean inunction method in the treatment of syphilis.
Calomel ointment, first prepared in France during the last century, contained 10 per cent of calomel in petrolatum. The British used 20 per cent of calomel in lard. A 30 per cent ointment with white petrolatum was introduced into the National Formulary V (1926) under the name of Ointment of Mild Mercurous Chloride. In N. F. VI (1936) the base was changed to equal parts of white petrolatum and hydrous wool fat.
Dr. Lewis C. Britt,1 chemist of the Oregon State Board of Pharmacy, first pointed out that the N. F. VI ointment gave a narrower inhibitory