Did Mary Blandy Know the 'Love Powder' She Gave Her Father Was Arsenic?

Mary Blandy was desperate to marry, but none of her suitors met the stringent standards set by her father -- until she met William Cranstoun, son of a Scottish peer. But her engagement to him turned out to be her downfall; William was already married. When it was divulged, her father did not approve the engagement, but William "had a method of conciliating [her father's] esteem" -- and it involved feeding her father a 'love powder' to soften him up a bit. The love powder turned out to be arsenic, and Mary killed her father by administering it. Though she claimed she didn't know, there were clues she maybe did. The question remains: Was she a partner to this crime, or wasn't she?
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