What scientific explanation was given by caporeal as to the cause of the mysterious behavior in Salem?

Answer 1

In the 2 April 1976 issue of Science magazine, Dr. Linnda Caporael suggested that ergot poisoning from grain contaminated with the fungus might have led to some of the incidents of hallucinations and strange physical sensations reported during the Salem Witch Trials. Ergot contains a toxin which resembles the potent hallucinogen Lysergic Acid Diethylamide (LSD) and it can remain toxic in bread baked with flour that has been tainted by it.

Note that her hypothesis is plausible but it has been both prominently disputed and defended by other scientists.