This is an area about which I know nothing. I heard a passing reference to it in a video about the history of Japan. This link should take you to the right moment in the video - it's at 4:42. If knowledge about how electricity could be used was present in Japan, why was this knowledge not used in any practical way? Many thanks for your time.
Japanese scholars actually did make practical use and study of the electrical machinery brought to Japan by the Dutch. However, this early form of technology was very limited in its applications, and the progress they made in their studies was superseded within a few decades by more modern technology and science from the West. So, Edo Period electrical research is just an interesting side story in scientific history, not the beginning of something greater.
The bit of electrical know-how that the Dutch brought to Japan was a variation on the Leyden jar: a set up that stores a static electric charge which can be then discharged at will. The Leyden jar was invented in 1745 in the Netherlands, and the concept had undergone a bunch of development in Europe. Some time around the late 1760s, the Dutch East Indian Company shipped one of the latest electrical machines to Nagasaki as a gift for the shogun. It arrived broken, and no one knew how to fix it. One of the shogunate's translators at Nagasaki, Zenzaburou Nishizaki, bought or was given the broken machine. He in turn sold it in 1771 to Hiraga Gennai, a polymath inventor/painter/naturalist/writer/researcher who was interested in everything.
Gennai today has a popular reputation in Japan something like Leonardo da Vinci in the West, in manga/anime/movies/novels/games, he's the mad inventor who can fiddle around with a few tools and make you a rocket ship out of spare parts. The legend is based on some real accomplishments, particularly his work on the electric machine, which he called the Elekitel (or as transcribed phonetically, the erekiteru.) It took six years and some consultation with a member of the Dutch embassy to the shogun to figure out how the machine worked, but once he did, he was able to build his own version. Gennai’s machine became a marvel. His version of the machine worked by “rubbing an insulated cylinder of glass (a commodity imported from the west at the time) against a piece of foil to produce a static charge.” (p. 84 “Hiraga Gennai: Tokugawa Japan’s Creative Genius as Author” in Virginia Review of Asian Studies by Christopher Smith, 2009.)
In 1795, Tachibana Nankei wrote a description of Gennai’s version of the machine.
The device called an erekiteru came to Japan twenty-three years ago. It is a machine for drawing fire from a person's body. Wheels are set within a box; it is just under an metre and an iron chain, five or six metres in length and ending in a looped handle, leads off. You have someone grasp the handle and then start the wheels rotating, so that power is transmitted along the chain. This provokes a reaction in the person, and little bits of paper brought up to them will move and dance of their own accord; if someone brings their hand close, you can hear a sound like spitting fat, and see a flame flying out. No-one who has yet to see the amazingness of this device will believe in it.
A photo of a reproduction of the machine.
Gennai made ten copies of his machine, and mostly used them for electrotherapy. The shock numbed areas of pain. However, Hiraga Gennai’s career ended in tragedy. His greatest patron lost his influence in the shogunate, then Gennai began to show signs of mental illness, at last murdering one of his students in what seems to have been an episode of pyschosis. Gennai died in prison in 1780, and as a result, his work wasn’t directly passed on. Other scholars had to derive the principles from the machines themselves, but by 1787, one of them: Morishima Chuuryou had published a complete design of the machine. He and others manufactured the machines for both electrotherapy and display as curiosities.
The first scholar after that to do scientific research with the machine was Hashimoto Soukichi (1736-1836). He’d read Western research on the matter, including a Dutch translation of some of Ben Frankin’s writings. He improved the design of the Elekitel, and recreated Western experiments with electricity. Most vividly, he got one hundred children from a nearby school to hold hands so he could send an electric shock through them.
Another researcher, Kawamoto Koumin (1810-1871) started work in the 1830s on understanding and using electricity. Working with outdated texts from the West, Kawamoto was discovering concepts already known in Europe, so his development of a voltaic pile didn’t change history, but shows how busy Japanese scholars were in developing uses for electricity.
With the opening of Japan to full commerce with the West, Japanese scholars were able to fully enter the mainstream of science. In the last days of the shogunate, however, there was one man who used the previous research to absolutely churn out practical inventions. Sakuma Shouzan is best known as a political and military theorist (and assassination victim), but he was also an inventor.
He fabricated silk-covered wire and created a telegraph apparatus in about 1850 or 1860 for communication experiments in his home town of Matsushiro (until quite recently, his experiments were dated to 1849, but now most investigators believe that they occurred after 1860). Sakuma also fabricated other devices, such as earthquake prediction apparatus and medical equipment. In his medical equipment, Sakuma made use of Faraday’s law of electromagnetic induction to generate a high voltage by an induction coil, and used it instead of the static charge of the Elekitel. (p. 6 in "Formation of Electrical Machinery Technology in the Edo Period of Japan")
That quote is from a seven-page article on this exact subject that so exactly fits what you're interested in that I'm very annoyed it's behind a paywall. I've gone over some of the highlights they mentioned, as well as added some background on Hiraga Gennai, but in the off-chance, you have library access,
is available in the Wiley Online Library, as linked.
