Cases of epithelioma have been cured by repeated painting with the acid nitrate of mercury, the morbid growth being destroyed in layers (Gay: British Medical Journal, i., 1862); and this mode of treatment is applicable with due care in instances where operation is not desirable. It has been used to the cervix uteri, but has sometimes caused severe salivation, so that it has not been generally adopted: bromine is more suitable.

Extending patches of lupus are often controlled by the nitrate, but it is not so useful in the erythematous, as in the ulcerative and discharging forms: its application is very painful, and should not be repeated more than once or twice weekly, and should be followed by soothing remedies. In chronic torpid ulcerative conditions, M. Lailler recommends an ointment containing the red iodide with iodide of potassium (about 7 gr. of each in 3 oz.), it is useful but irritant: it may be applied stronger to nonulcerative forms. Cinnabar is combined with arsenic in "Cosme's paste," which is very useful for superficial lupus patches about the face: three applications are usually made, for twenty-four hours each time (v. p. 45).