Isinglass soaked in water and dissolved in spirit, 2oz. (thick); dissolve in this 10 grains of very pale gum ammonia (in tears) by rubbing them together; then add 6 large tears of gum mastic, dissolved in the least possible quantity of rectified spirit. When carefully made, this cement resists moisture and dries colorless. Keep in a closely stopped vial.

Jeweler's Turkish Cement

Put into a bottle 2 oz. of isinglass and 1 oz. of the best gum arable; cover them with proof spirits, cork loosely, and place the bottle in a vessel of water, and boil it till a thorough solution is effected; then strain for use; best cement known.