This is a pink-colored salt, useful, especially with zinc white, for exposure to sulphur gases. The following is the formula for its use: Sulphate of manganese 1 part, calcined sulphate of zinc 1 part, and acetate of manganese 1 part. These must be ground and sifted into a fine powder, and then dusted over 97 parts of zinc white. Another method for its use is: 6 to 8 ounces of sulphate of manganese to 100 pounds of ground zinc white paint, the powder thoroughly mixed with a portion of the paint, and this portion thoroughly mixed with the whole. Unless care is taken in the mixing, the work may be spotted.