[eesmith]

Related to, perhaps, but not so relevant as my comment was in response to mousethatroared writing 'As I understand it, English lost a lot of characters when the movable type printing press was created.'

Also, the long s is not a letter of the English alphabet but rather a form of the letter 's', like how ꝛ (the r rotunda) is an archaic variant form of the letter 'r'. https://en.wikipedia.org/wiki/R_rotunda

Similar, I believe, to how Greek σ when in the word-final position is ς, but both are lower-case sigma.