Which gas did Humphrey Davy popularize for medical use?

• A. Nitrous oxide
• B. Oxygen
• C. Hydrogen
• D. Argon

Answer: (A)

Nitrous oxide, known as laughing gas, is the gas Humphrey Davy popularized for medical use. Davy, a chemist, explored the properties of nitrous oxide in the late 1790s and early 1800s and gave public demonstrations showing that inhaling the gas could cause euphoria and relief from pain. He argued that this pain‑relieving effect could be valuable in medical procedures, especially dentistry and surgery, and published ideas encouraging its use as an anaesthetic. This helped spark interest in anesthesia in medicine, even though it would take longer for nitrous oxide to become a routine clinical anaesthetic. The other gases listed don’t fit this historical pattern: oxygen is crucial for life but not a painkiller in surgical contexts; hydrogen is not used as an anaesthetic; argon is an inert gas with no medical use in this sense.