But on the other hand, he was interested in Kyurigaku (learning of plumbing the scientific principles), influenced by a nature philosopher Baien MIURA, and at around 40, he learned Dutch using "Yakken" (Nederduitsche Taal, Japanese first Dutch-Japanese dictionary literally named 'key to translation') written by Fuzan FUJIBAYASHI to learn the natural science in Europe.
が、一方で、自然哲学者・三浦梅園の影響により窮理学に関心を持ち、40歳頃から藤林普山の『訳鍵』を手に入れてオランダ語を修得し、ヨーロッパの自然科学を学んだ。