He graduated in 1788, completed his medical education in London, and, returning for a short time to his parents and wrote his treatise on optics for the Encyclopædia Britannica.
They were married in March 1795, and as he was in Liverpool endeavouring to arrange for a passage to America a casual invitation to deliver lectures on natural philosophy changed the current of his life.
His depression prevented him from carrying out the important post of professor of natural philosophy and chemistry at the Royal Institution, to which he was appointed in October 1799.
Those, at least, which were published after his death under the title of Zoonomia, or the Laws of Animal Life (1804), though full of knowledge and exceedingly clear in style, are too technical for a popular audience.
A subscription was raised, and his Royal Institution lectures were published for the benefit of his two infant daughters, one of whom was to be the poet Mrs. Catherine Grace Godwin.
His gravestone and coffin plate were recovered during an archaeological excavation at the former 18th and 19th century burial ground, in the preparatory phases of work for the new HS2 rail line.