What experiments did Sir Humphry Davy perform with nitrous oxide?

As chemical superintendent of the Pneumatic Institution, Sir Humphry Davy conducted extensive research into the properties and physiological effects of nitrous oxide.1

His primary experimental objectives included:

• Testing Pathogenic Claims: Davy investigated the hypothesis that nitrous oxide was the "principle of contagion"—a substance believed to cause diseases. To test this, he prepared the gas and inhaled it himself.1
• Documenting Physiological Effects: Beyond his own self-experimentation, he persuaded various scientific and literary figures, such as Samuel Taylor Coleridge, Robert Southey, and Peter Mark Roget, to inhale the gas and report their experiences.1
• Chemical Analysis: He performed detailed investigations into the composition of nitrogen oxides, acids of nitrogen, and ammonia.1

Davy published his findings in 1800 in the work Researches, Chemical and Philosophical, Chiefly Concerning Nitrous Oxide, or Dephlogisticated Nitrous Air, and Its Respiration. This research successfully demonstrated the gas's physiological effects, including its ability to produce euphoria and insensibility to pain, which eventually led to its use as an anesthetic.21