Shin (letter) languages, as follows: In the Arabic alphabet, ' is at the original (21st) position in Abjadi order. A letter variant ' takes the place of Samekh at 15th position. "" represents , and is the 13th letter of the modern alphabet order and is written thus: The Arabic letter "šīn" was an acronym for "something" ( "šayʾ(un)" ) meaning the unknown in algebraic equations. In the transcription into Spanish, the Greek letter "chi" (χ) was used which was later transcribed into Latin "x". According to some sources, this is the origin of "x" used for the unknown in the equations.
Alphabet of the Magi the prophets used this letter and that they were forbidden to divulge it to mortal man." Thet alphabet is described in the pseudo-Paracelsian "Archidoxis magica", translated into English by R. Turner (1656). S.L. MacGregor Mathers included it in his 1888 edition of the "Key of Solomon" (plate XV) under the name "Alphabet of the Magi." Alphabet of the Magi Alphabet of the Magi is the modern name of a variant of the Hebrew alphabet used for inscriptions in talismans in 17th-century occultism. It is based on a variant of the Semitic alphabet given by Theseus Ambrosius (1469–1540) in his "Introductio