Final answer:
The first local anesthetic introduced was diethyl ether in 1846.
Step-by-step explanation:
Local anesthesia is a type of anesthesia that is used to block sensation in a specific part of the body, allowing medical procedures to be performed without causing pain or discomfort to the patient. Unlike general anesthesia, which induces a state of unconsciousness, local anesthesia specifically targets a localized area.
The first local anesthetic introduced was diethyl ether, by William Morton, a Boston dentist, in 1846.
Inhalation of ether vapor produces unconsciousness by depressing the activity of the central nervous system.
Therefore, the correct answer is 1846.