Does anyone know the proper name for the old printed 's' that looks like an 'f'?

Question

This has been driving me nuts for years! Please can somebody tell me?

Answer 1

It is known as a 'long s'

for a full description and discussion see

http://en.wikipedia.org/wiki/Long_s

Answer 2

The long 's' is derived from the old Roman cursive medial s, which was very similar to an elongated check mark. Eventually it got a more vertical form.
The long 's' is subject to confusion with the minuscule 'f', sometimes even having an 'f'-like nub at its middle, but on the left side only, in various kinds of Roman typeface and in blackletter. There was no nub in its italic typeform, which gave the stroke a descender curling to the left—not possible with the other typeforms mentioned without kerning.
The nub acquired its form in the blackletter style of writing. What looks like one stroke was actually a wedge pointing downward, whose widest part was at that height (x-height), and capped by a second stroke forming an ascender curling to the right. Those styles of writing and their derivatives in type design had a cross-bar at height of the nub for letters 'f' and 't', as well as 'k'. In Roman type, these disappeared except for the one on the medial 's'.
The long 's' was used in ligatures in various languages. Three examples were for 'si', 'ss', and 'st', besides the German 'double s' 'ß'.
Long 's' fell out of use in Roman and italic typography well before the end of the 19th century; in English the change occurred in the decades before and after 1800. In most countries ligatures vanished as well. Typographers have presently revived ligatures in seriffed and sans-serif text fonts, as well as many kinds of display types. For example, some text fonts have an 'st' ligature made up of a terminal 's' with a small bulbous curl connecting the two letters at the top, unlike ligatures using a long 's', which joins directly to the 't' by an extension of the long s ascender.
Long 's' survives in German blackletter typefaces. The present-day German 'double s' 'ß' (ess-zett) is an atrophied ligature form representing either 'ſz' or 'ſs' (see ß for more). Greek also features a normal sigma 'σ' and a special terminal form 'ς', which may have supported the idea of specialized 's' forms. In Renaissance Europe a significant fraction of the literate class were familiar with Greek.