MB ChB Manch 1889; LSA 1888.
Merrall studied medicine at Owens College Manchester, where he was demonstrator of anatomy. He was surgeon to Guernsey Town Hospital and physician to the Imperial Hydropathic at St Anne's on Sea. Merrall was later in consulting practice in St Anne's and Manchester. He was a fellow of the Royal Society of Medicine, MMS and the Society for the Study of Inebriety.