What does the 'H' stand for in 'Jesus H Christ'?

Jack Hurley, Leeds W.Yorks

• In Catholic churches, one often finds the name of Jesus Christ piously represented by the Greek contraction IHC XC, where the C represents the late-Classical form of Sigma. This is known as a Christogram (in Greek Orthodox usage, the preferred Christogram is ICXC). In partially Latinised form, the IHC component is rendered JHC or JHS. This is the origin of the interjection, which seems to imagine that H is Jesus' middle initial, and Christ his surname, rather than his title (ho khristos: the anointed).

  John Bennett, Glasgow, Scotland