化学工学: chemical engineering

液滴: drop (of liquid)

(historical) researchers who were employed by Tokugawa shogunate and studied Japanese and/or Japan-related history (Japanology).

Kyūjitai form of 言語学 (“linguistics”)

etymology (study of the historical development of languages, particularly of individual words)

language study / linguistics

linguistics

Kyūjitai form of 語源学: etymology

Kyūjitai form of 地名学 (“toponymy”)

toponymy