As described in his Philosophical Dictionary in 1764, Voltaire conducted this peculiar experiment to dispel an equally strange, yet persistent, myth dating back to ancient times: that bull’s blood was a deadly poison.

“If a man in his folly tastes the fresh blood of a bull, he falls heavily to the ground in distress, over-mastered by pain,” the Greek physician Nicander wrote in the second century BC.

Nicander was echoing earlier Greek writers like Aristotle, who described bull’s blood as the “quickest to coagulate” of all animal bloods (a claim unsupported by modern research, which has found that the blood of cattle clots more slowly on average than that of some other animals such as pigs and sheep).

However, Ancient Greek scholars believed that bull’s blood solidified rapidly in the throat when swallowed, causing fatal asphyxiation. “The blood congeals easily,” Nicander explained, “and, in the hollow of [the victim’s] stomach, clots; the passages are stopped, the breath is straitened within his clogged throat, while, often struggling in convulsions on the ground, he gasps bespattered with foam.” To treat this gruesome condition,

Nicander recommended several remedies, of which some (fresh figs in vinegar) sound easier to obtain than others (the milk of a hare or deer).