Which British chemist published "Directions for Impregnating Water with Fixed Air" in 1772?

The British chemist who published “Directions for Impregnating Water with Fixed Air” in 1772 was Joseph Priestley.

In the pamphlet, Priestley described a method for dissolving “fixed air”—his term for carbon dioxide—in water. He generated the gas during experiments with fermentation and transferred it into water, producing an early form of artificially carbonated water. The work helped establish the scientific foundation for soda water, although Priestley was investigating chemistry rather than developing a modern soft-drink brand.

Priestley was also a theologian, philosopher, educator, and prolific experimenter. His gas research included major investigations of oxygen, which he called “dephlogisticated air” within the phlogiston framework then common in chemistry. That terminology is why Antoine Lavoisier is sometimes brought into the story: Lavoisier later helped explain oxygen and combustion using a newer chemical system, but he did not author this 1772 carbonation pamphlet.

The phrase “fixed air” can sound like ordinary air, but it referred specifically to carbon dioxide. Priestley’s practical instructions made the title an important milestone in the history of carbonated drinks.