Chemist Sir Humphry Davy is known for his work with nitrous oxide, or laughing gas. That early part of his career is the focus of part one of this two-parter.
Research:

Peter Kropotkin's Mutual Aid, Part 1
45:03

SYMHC Classics: Haymarket Riot
37:40

Behind the Scenes Minis: Serving Lip and Ethics
26:19