For a glaze, dissolve 1 part of acetate of lead (sugar of lead) in 5 parts of water, and dip the pipes into the solution or apply with a brush; then, after drying, tire at a low red heat. Another glaze is made by melting together in a crucible 1 part of carbonate of potash and five parts of borax; pour the melted mass into an iron plate, powder it very fine, and mix w.ith turpentine. Apply the wash with a brush and fire as above.