Nitrate of Copper. CuO, NO3, 3 HO. A powerful caustic and escharotic, stated by Dr. Fleming* to be very superior to all other caustics, in Lupus, Malignant Ulcers, and also in those small excavated semi-phagedenic Ulcers which occur on the genital organs, both of the male and female. It is very deliquescent, and can only be applied in a liquid state, the surrounding parts being well protected by oil, &c.