The Life of John Walker, M.D., Graduate of the University of Leyden ; Licentiate of the Royal College of Physicians of London ; and Late Director of the Royal Jennerian and London Vaccine Institutions. By John Epps, M.D., Graduate of the University of Edinburgh ; Lecturer on Materia Medica and Chemistry ; Director of the Royal Jennerian and London Vaccine Institutions ; and Member of the Committee of the Westminster Medical Society, &c