ptomaine: [19] Ptomaine denotes etymologically ‘matter from a corpse’. It comes via French ptomaïne from Italian ptomaina, which was based on Greek ptōma ‘corpse’. This in turn was derived from the verb píptein ‘fall’, and originally meant literally ‘fallen body’. The term was coined to name substances produced by decomposing flesh.
1880, from Italian ptomaina, coined by Professor Francesco Selmi of Bologna, 1878, from Greek ptoma "corpse," on notion of poison produced in decaying matter. Greek ptoma is literally "a fall, a falling," via the notion of "fallen thing, fallen body;" nominal derivative of piptein "to fall" (see symptom). Incorrectly formed, and Selmi is roundly scolded for it in OED, which says proper Greek would be *ptomatine.