Braid became interested in mesmerism in November 1841, when he observed demonstrations given by a traveling mesmerist named Charles Lafontaine (1803 - 1892). Convinced that he had discovered the key to understanding these phenomena, Braid began giving lectures the following month.
In 1843 he published Neurypnology: or the Rationale of Nervous Sleep, his first and only book-length exposition of his views. In this book he coined the words "hypnotism", "hypnotize", and "hypnotist", which remain in use. Braid thought of hypnotism as producing a "nervous sleep" which differred from ordinary sleep. The most efficent way to produce it was through visual fixation on a small bright object held eighteen inches above and in front of the eyes. Braid regarded the physiological condition underlying hypnotism to be the over-exercising of the eye muscles through the straining of attention.
He completely rejected Franz Mesmer's idea that a magnetic fluid caused hypnotic phenomena, because anyone could produce them in "himself by attending strictly to the simple rules" that Braid laid down.
Alan Gauld, A History of Hypnotism, (Cambridge University Press, 1992).