5. Horace Wells
Horace Wells was a dentist in Connecticut who is considered the father of laughing gas due to his discovery that nitrous oxide could be used to dull pain during procedures. He first tested the theory on a volunteer patient, who inhaled the gas which put him into a stupor. While under the influence of the gas, Wells slashed his leg and the patient claimed to have no pain.
In an attempt to further prove his theory on nitrous oxide, Wells became a test subject himself and had another dentist administer the “laughing gas” on him while undergoing a root canal. After the gas wore off, Wells claimed he felt nothing and began using the treatment on his patients. This eventually evolved into what is now used in most surgery centers and dentist offices.