The
diagonal fraction bar in
mathematics. Also called
virgule or
slash. This
symbol was used to
replace the
horizontal fraction
bar, sometimes referred to as a
vinculum, due to the
typographic difficulty imposed by the horizontal bar which requires three
terraces of
type.
An early written example of this usage can be found in a 1718 ledger by Thomas Twining. In his article "The Calculations of Functions" from 1845 and published in the Encyclopaedia Metropolitana, De Morgan recommended the use of the solidus.
Also, an ancient Roman gold coin used until the fall of the Byzantine Empire and introduced by Constantine.