In France, a chemist named Pilatre de Rozier tested the flammability of hydrogen by gulping a mouthful and… — Bill Bryson

In France, a chemist named Pilatre de Rozier tested the flammability of hydrogen by gulping a mouthful and blowing across an open flame, proving at a stroke that hydrogen is indeed explosively combustible and that eyebrows are not necessarily a permanent feature of one's face.

p. 53Source: Wikiquote · CC BY-SA 4.0