E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Aqua Tofana or Acqua Tofanca.
A poisonous liquid much used in Italy in the seventeenth century by young wives who wanted to get rid of their husbands. It was invented by a woman named Tofna, who called it the Manna of St. Nicholas of Bari, from the widespread notion that an oil of miraculous efficacy flowed from the tomb of that saint. In Italian called also Aquella di Napoli.