Areas of study included telepathy, hypnotism, Reichenbach's phenomena, apparitions, hauntings, and the physical aspects of Spiritualism such as table-tilting, materialization and apportation. In the 1880s, the Society investigated apparitional experiences and hallucinations in the sane. Among the first important works was the two-volume publication in 1886, "Phantasms of the Living" which was largely criticized by scholars. In 1894, the "Census of Hallucinations" was published which sampled 17,000 people. Out of these, 1,684 persons admitted to having experienced a hallucination of an apparition. The SPR became the model for similar societies in other European countries and the United States during the late 19th century.