He contributed articles to the New England Journal of Medicine and Surgery, but is best known for a discourse before the Massachusetts Medical Society in 1813, entitled a “Dissertation on the Natural History and Medicinal Effects of Secale Cornutum, or Ergot,” which was republished in London, and translated into French and German.
One of the most prominent theories is that victims suffered from ergot poisoning, which was known as St. Anthony's fire in the Middle Ages.
Like the ergot alkaloids in some monocot plants, the ergoline alkaloids found in the plant Ipomoea asarifolia (Convolvulaceae) are produced by a seed-transmitted epiphytic clavicipitaceous fungus.
Ergotamine is a secondary metabolite (natural product) and the principal alkaloid produced by the ergot fungus, Claviceps purpurea, and related fungi in the family Clavicipitaceae.
Ergot of Rye is a plant disease caused by the fungus Claviceps purpurea, which Caporael claims is consistent with many of the physical symptoms of those alleged to be afflicted by witchcraft.
Key genes and enzymes for ergot alkaloid biosynthesis have been identified in epichloae and include dmaW, encoding dimethylallyl-tryptophan synthase and lpsA, a non-ribosomal peptide synthetase.