The following are reliable recipes for miscellaneous cements. A cement for repairing an amber mouthpiece, broken in two, may be made by dissolving sufficient gum copal in ether to form a syrupy fluid. The broken portions should be slightly warmed, the cement qniekly applied, and the two pieces brought closely together and bound by wire. The cement sets quickly, and the excess may be pared off with a sharp knife. Another: Heat the surfaces to be joined and apply boiled linseed oil. Clamp firmly until united. Instead of the boiled oil, a solution of potash, or a solution of mastic in linseed oil, may be employed. A cement for fixing the tangs of knife-blades into the handles is made by mixing 4 parts of resin, 1 part of beeswax, and 1 part of plaster-of-Paris, or by mixing resin with a little white sand. Put the cement powder into the hole, heat the tang, and press home. The following is a cement for mending cracked or broken glass lamps to hold paraffin oil. Mix plaster-of-Paris with white of egg and a little vinegar. Allow this twents'-four hours after applying in which to become hard. Another; Mix 3 parts of resin, 1 of caustic soda, and 5 of water with half their entire weight of plaster-of-Paris. Use at once, and allow forty-five minutes in which to set.

For attaching the brass rim either of a glass or an earthenware lamp, powdered alum forms a simple but thoroughly reliable cement. Clean the rim and neck from grease, invert the rim, and fill its cavity with powdered alum, and place on the top of a hot range or stove. When the alum begins to get pasty, press the neck of the lamp firmly into place, remove from the stove, and set aside to cool. In about five minutes the lamp will be ready for use. Auother: 1 part of plaster-of-Paris well mixed with 2 parts of resin soap. Zinc white or slaked lime can be substituted for the plaster-of-Paris. Another: Plaster-of-Paris worked up with a saturated solution of alum in water.