68. The visarga is not original

The visarga is not original, but always only a substitute for final s or r, neither of which is allowed to maintain itself unchanged (170 ff.). It is a comparatively recent member of the alphabetic system; the other euphonic changes of final s and r have not passed through visarga as an intermediate stage. And the Hindu authorities are considerably discordant with one another as to how far ḥ is a necessary substitute, and how far a permitted one, alternative with a sibilant, before a following initial surd.