From A Blast From the Past: Aqua Tofana: slow-poisoning and husband killing in 17th century Italy.

The story as it is commonly told is this: Aqua Tofana was the creation of a Sicilian woman named Giulia Tofana, who lived and worked in Palermo in the first half of the 17th century. It was a limpid, harmless-looking liquid, a scant four to six drops of which were “sufficient to destroy a man.” Its principal ingredient was arsenic, and, while its use spread throughout much of southern Italy, it was typically administered by women to their husbands, most commonly in order to come into their fortunes – poisons were often known as “inheritance powders” in those days.

The very existence of Aqua Tofana was, thus, a severe challenge to what was then agreed to be the natural order – a world in which men ruled as petty tyrants over their own families, and even the most aristocratic of daughters were chattels to be auctioned off into often loveless marriages. For this reason, generous allowance needs to be made for contemporary misogyny when we think about this tale; one of the few constants in the various portraits of events is the depiction of Tofana and her gang as hags, and their female customers as faithless Jezebels. [continue]

Italy. Poison. Murder. History. What more could you want? This is a well-written, well-researched, and thoroughly fascinating article.