Without this last accidental discovery on our list, medical treatments would be a big pain -- literally.
Although the true discoverer of anesthesia is contested, the people who contributed to its development and use were inspired by similar accidental observations.
Crawford Long, William Morton, Charles Jackson and Horace Wells all come to mind when talking about anesthesia. These men realized that in some cases, ether and nitrous oxide (laughing gas) inhibited pain in people under their influence.
In the 1800s, inhaling either of these compounds was somewhat popular for both recreation and entertainment. By witnessing and even partaking in these events, often called "laughing parties" and "ether frolics," anesthesia's founding fathers learned more about how these experiences affected people's perceptions of pain.
One example in particular demonstrates the accidental discovery of these compounds used to prevent pain in the medical field. In 1844, Horace Wells attended an exhibit and witnessed a participant injure his leg while under the influence of laughing gas. The man, whose leg was bleeding, told Wells that he didn't feel any pain.
After his accidental discovery, Wells used the compound as an anesthetic while he removed his tooth. From there, anesthesia's use during medical procedures and surgeries took off. Wells, Morton and Jackson began to collaborate and use anesthesia in dental practices, while Crawford Long used ether for minor surgeries.
Check out our other countdowns of fascinating inventions from throughout history.