Davy's career after his work in nitrous oxide included the invention of a miner's lamp designed to make mining safer. This invention came with a bit of controversy.
Research:

Behind the Scenes Minis: Percy Theories
16:43

Percy Fawcett, Manuscript 512, and a Lost City in the Amazon, Pt. 2
37:10

Percy Fawcett, Manuscript 512, and a Lost City in the Amazon, Pt. 1
34:05