Convert from onca [Portuguese] to flask

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 (flask)
The flask is a commercial unit of weight formerly used to measure liquid mercury (or quicksilver, as it was called). The flask was equal to 76.5 pounds avoirdupois, which is equivalent to almost exactly 34.7 kilograms.