Convert from onca [Portuguese] to scruple [troy]

Unit Definition (onca [Portuguese])
The onça, once, oncia, onza is traditional names for the ounce unit in Romance languages. The Portuguese onça and Spanish onza equal 1/16 libra or about 28.69 grams (1.012 ounce).

Unit Definition (scruple [troy])
The scruple is a unit of weight in the traditional (troy) system used by English apothecaries, equal to 20 grains, 1/24 troy ounce or approximately 1.2960 gram.