The long or medial s (ſ) is a form of the minuscule letter s
that was formerly used when the s occurred within or at the
beginning of the word, for example ſinfulneſs ("sinfulness").
The modern letterform was called the terminal or short s. The
medial s was subject to confusion with the minuscule f,
sometimes even having an f-like nub appended to its middle, in
various derivatives of Roman typeface and in blackletter. There
was no nub in its typeform in italics, which also gave the
stroke a descender which curled to the left, something which
could not be given to the other typeforms mentioned without
kerning. The nub derived from its form in the blackletter style
of penmanship. What looks like one stroke to us was actually a
wedge pointing downward, whose widest part was at that height,
capped by a second stroke forming a curled ascender to the
right. Those styles of writing and their derivatives in type
design not only had a cross-bar at height of the nub in the form
of the letters f and t, but also k, and h