Born into a low-ranking samurai family from Sanuki Province (讃岐国 Sanuki-no kuni, modern-day Kagawa Prefecture in Shikoku), Hiraga Gennai (平賀源内, 1728-1780) was also known as Kunitomo (国倫) and under his pen names Fūrai Sanjin (風来山人, “Wind Straddler”), Kyūkei (鳩渓, “Valley of Doves”), Fukuchi Kigai (福内鬼外, “Demons Outside, Good Luck Inside”) and Tenjiku rōnin (天竺浪人, “Traveller from Elsewhere”).
He first studied medicinal herbs in Ōsaka with Toda Kyokuzan (戸田旭山, 1696-1769) and rangaku (蘭学, “Dutch” or “Western” studies) in Nagasaki, and moved to Edo in 1757, where he studied with Tamura Ransui (田村藍水, 1718-1776), a Confucian philosopher and pharmacologist. He published Butsurui hinshitsu (物類品隲, “Classification of Various Materials”) in 1763, as well as two satirical novels, Nenashigusa (根無草, “Rootless Grass”) and Fūryū Shikōden (風流志道軒伝, “The Dashing Life of Shidōken”), which founded the roots of kokkeibon (滑稽) and dangibon (談義本 literature, a humorous type of novels popular in the eighteenth and nineteenth century, often instructional and containing a lesson to be learned.
Hiraga engaged in a variety of experiments, such as weaving asbestos (kakanpu) in 1765, creating modern thermometers (kadankei) and an electrostatic generator (エレキテル erekiteru) that was derived from a Dutch model he had acquired during his second trip to Nagasaki in 1770. His elekiter consisted of a small box that used the power of friction to generate electricity and store it.
Hiraga also studied European weaving methods, ceramics and painting techniques. He was interested in mining and prospected for ores, trying in vain to have an old copper mine in Akita opened in 1773. He later tried to open another mine, this time to exploit iron.
His later fate remains shrouded in mystery: according to one story, he killed one of his disciples with a blow of his sword in a fit of ire and out of desperation over lacking support and recognition of his intellect. Another legend has it that he killed two head carpenters when he undertook repair work at his daimyō‘s mansion. Completely intoxicated, he accused the two unfortunate men of having stolen his repair plan. Whatever the truth, he was sentenced to prison, where he died of tetanus at the age of fifty-two. Sugita Genpaku (杉田玄白), a Japanese scholar and friend, tried to arrange a funeral for Hiraga, but the bakufu denied his request, resulting in the obsequies be held without body and tombstone. His body was buried in the Sosenji Temple in Taitō Ward, Tokyo.
- Tomb of Hiraga Gennai
- Hiraga Gennai shu (a digitalised version of a Japanese biography on Hiraga Gennai by the University of Toronto Cheng Yu Tung East Asian Library: PDF 33.5 M)
- Hiraga Gennai Memorial Museum (in Japanese)
Hiraga Gennai (平賀源内)