English polymath who contributed to the fields of vision, light, solid mechanics, energy, physiology, musical harmony, and Egyptology.
He started studying medicine in London in 1792 and earned a degree of doctor of physics in 1796 before starting his own career as a physician in 1799.
He was elected a foreign member of the Royal Academy of Sciences in 1828.
He was born the eldest of ten children in a Quaker family in Milverton, Somerset.
He was called a "truly original genius" by fellow scientist John Herschel.