What I know* is that around 1979, a woman cut open the seed coatings on a fairly large number of apple seeds, say, 2-3 apples worth, and fed them to her six year old daughter.
What I don't know is what the heck this was all about. There is some evidence that she held some animus towards the child. She also recently had lost the child's younger sister to a childhood disease, and had possibly enjoyed her position as a mother of a critically ill child. When discussed in another context, Munchausen's by proxy was brought up, but seriously, I have no clue, and that's not even really the level of analysis I'm looking for (I'm including it only because I think it's useful background in that yes, it's not unreasonable to think that this was a poisoning attempt of some kind, though, WTF? She certainly went on to behave poorly and inconsistently towards her other children.)
In purely practical terms, based on current medical knowledge, as far as poisoning attempts go, it is pathetic. There is not enough cyanide in that number of apple seeds to have an effect.
What I'm wondering is the knowledge base the mother might have had at that time, especially from popular culture. She returned to school after the death of her younger child, and took classes in both nutrition and microbiology, though this didn't go very far, and I think the timing of the aforementioned event wouldn't have been very far into her return to school. While she thought of herself as scientific, she has generally been quite credulous and receptive to things in popular culture.**
I've looked a little at the scientific papers referring to cyanide poisoning, and particularly cyanide poisoning in fruit seeds from the 1970s, and googled variations of cyanide poisoning 1970s (and was reminded of Jonestown). I'm aware that the amount of cyanide in apple seeds has been variously misreported (though I haven't run across such misreporting in the primary literature) but I don't have a sense of what was common knowledge at the time.
Can anyone add some background?
* Well, in part I am exploring the unreliable nature of memory, so take "know" with a grain of salt, but I'm reasonably certain, and there is some supporting evidence.
** She objected to family members being organ donors on the grounds that people who receive their organs will also receive their memories. This, I swear, is the joy of non-fiction.