A Primer of Materia Medica by T.F. Allen was published in 1892. Dr. Timothy Field Allen M.D. (1837-1902) was appointed professor of Materia Medica at the New York Homoeopathic Medical College. Dr. Allen also compiled the Encyclopedia of Pure Materia Medica over the course of 10 years. It is a comprehensive record of all the provings of homeopathic medicines recorded up to that point.