The Long s (ſ) is a former olden sundering of the "s" rune that was brooked when the s rune was in the beginning and in the middle of words. This frothering of the s rune was forsaken from the art of writing shortly before the 19th hundredyear began. The laws for the long s are manifold and are also sundered by the tongue that it is being written in. For byspel, one must never make an ettle to use the Long s at the end of words or soon after the short s, nor should the long s be brooked before the runes b and k, and before and after the f rune.
The long s was said to have arisen in the days when Old Roman Hand was still being brooked. In Roman runesets, the Long s has a look which is akin to the f rune, but the otherness between the two runes can be unfolded if one were to look closely at the two.