At the Arsenal building near the southeast corner of Central Park, New York’s Central Park Zoo was less than a two-mile walk north of the dental offices of Dr. Ferdinand Hasbrouck. Perhaps monkeys at the zoo inspired Hasbrouck to advertise with this trade card titled, “Tickle me under the Chin.” Having earned his dental doctorate in Philadelphia, Hasbrouck delighted in poking fun at Manhattan’s Colton Dental Association, many of whose dentists lacked academic training in either dentistry or anesthetics. (Copyright © the American Society of Anesthesiologists’ Wood Library-Museum of Anesthesiology.)
Source: Anesthesiology