Joseph Henry independently discovered electromagnetic induction in 1831, the same year as Faraday, and was the first to identify and describe self-induction — the phenomenon by which a circuit generates an electromotive force opposing the change in its own current. The SI unit of inductance bears his name (henry). Faraday published first and developed the theoretical framework with greater depth and system, which gave him canonical priority. In the Wikinventia corpus, Henry is one of the best examples of a parallel discoverer whose work was real, simultaneous, and technically notable, but whose memory was subordinated to whoever published first.