Coniine is a poisonous alkaloid found in poison hemlock and the Yellow Pitcher Plant, and contributes to hemlock's fetid smell. It is a neurotoxin which disrupts the central nervous system. It is toxic to all classes of livestock and humans; less than 0.2g (0.007oz) is fatal to humans, with death caused by respiratory paralysis. It is claimed that Socrates was put to death by way of this poison in 399 BC.