Convert from ons [Dutch] to dram [apothecaries]

Unit Definition (ons [Dutch])
The ons is a Dutch unit of weight or mass, now used as a metric unit equal to the hectogram (100 grams, or about 3.5274 ounces).

Unit Definition (dram [apothecaries])
The dram [apothecaries] is a unit of weight in the traditional system of English apothecaries, equal to 60 grains, 3 scruples, 1/8 troy ounce, or approximately 3.8879 gram. See troy weights for additional information. The apothecaries' dram is sometimes abbreviated dr. ap. to distinguish it from the avoirdupois dram. It is equivalent to about 2.1943 avoirdupois drams. There is a similar Italian unit, the dramma, equal to 72 grani or roughly 3.5 grams.