Antique opium weights have a history dating back hundreds of years. They were used for measuring opium sap, and also to weigh other high value products such as silver ingots, pearls, rubies and costly medicines among other substances. The weights were made using the lost wax technique, and the molten alloy usually consisted of zinc, iron, nickel and silver. Usually they were depictions of either bird or beast. The rare set of bronze birds seen here are called Hintha / Hamsa distinguished by the pointed beak which curves down at the tip. The two largest have handles attached to the back of the head and to the end of the curled tail feathers. They have an excellent old patina. Burmese weights have deeply symbolic forms. The Bird is associated in Buddhism with spiritual purity and gentleness. It is considered a link between heaven and earth. Legend proclaimed that the Bird could distinguish between pure and impure alloys and accurately reflect mass.