The Book on Mediums, also known as The Mediums Book, was written by Allan Kardec and originally published in 1861. It is the widely respected follow up to The Spirits Book which was published in 1857 and is the second in a series of five books that Kardec wrote that are collectively known as the 'Spiritist Codification'. In the 1850's, whilst investigating the afterlife, Kardec communicated in s?ances with a collection of spirits named 'The Spirit of Truth' who discussed many important topics such as life after death, good and evil, the nature of the universe, the origin of spirits, and many other subjects. The Spirit of Truth' allegedly counted many of history's great thinkers amongst its number such as Thomas Aquinas, Voltaire and Augustine of Hippo. Over time and after several sessions with the group Kardec had gathered enough information to convince him of life after death and he was compelled to spread the teachings of 'The Spirit of Truth'. He 'codified' their comments and listed them as answers to questions and this forms the content of his teaching. The Books on Mediums is intended to be an essential guide to mediumship for mediums and those interested in the spirit world. The book covers the different types of mediumship including, table-turning, incorporation of spirits, haunted houses, transfiguration, apparitions, psychography and telekinesis. It explains how to deal with manifestations and how to guard against frauds, charlatans, and skeptics alike. The book warns against the perils of un-guided mediumship, possession, and obsession that often go hand in hand with the beautiful revelation that spiritual communication can reveal. Some of Kardec's advice found in the book include; Do not believe the spirit to be who he purports to be unless there is evidence supporting his claim, but even then, wait till others confirm what one has said. Do not judge the spirits by their purported names, but by the quality of the morals and the philosophy found in tlcĄ