trained Morse code operators copy messages conversing

Sign languages use facial expressions as part of grammar, not merely to convey emotion. In American Sign Language, raised eyebrows commonly mark yes-or-no questions, while other facial patterns help distinguish different question types. The face works alongside the hands to encode linguistic information. A sentence can change meaning even when the hand signs stay the same.

In 1804, Japanese surgeon Hanaoka Seishū performed breast surgery using a herbal anesthetic preparation that rendered his patient unconscious. This was decades before ether anesthesia became established in Western surgery. Hanaoka's method was developed within a different medical tradition and did not become the basis of modern inhaled anesthesia, but it demonstrates that surgical anesthesia has more than one historical origin.