Devanagari Sa स

Sa is the thirty-second consonant of the varnamala, the dental sibilant and the last of the three, made with the tongue at the teeth. It is the commonest of the sibilants and the one an English speaker produces without adjustment. Its behaviour at the ends of words is one of the more intricate parts of Sanskrit sandhi: a word-final dental sibilant is very often replaced by the visarga, a breath written as two dots to the right of the letter, and what it becomes before a following word depends on the sound that word begins with. Recovering the underlying sibilant from a visarga is a routine part of reading Sanskrit and one of the earliest things a learner is drilled on, because word-final sibilants are extremely common in the nominal endings.

The letter is also the source, by rule, of most occurrences of the retroflex sibilant, in the same way the dental nasal is the source of most retroflex nasals. Two of the three retroflex letters outside the stop classes are therefore derived rather than inherited, which says something about how much of written Sanskrit is the visible output of the language's own machinery. The letter also carries a large share of the language's grammatical information, since the sibilant appears in the endings of several noun cases and in the marks of two tenses. A reader who mishandles it at a word join therefore misidentifies the grammatical form as well as the sound, which is why the rules governing it are drilled early and at length.

The visarga is not a letter of the varnamala. It is a mark, written as two dots, standing for a voiceless breath that appears chiefly where a word-final sibilant or r has been replaced, and its treatment before a following word is governed by a body of rules. Together with the anusvara, the dot standing for a nasal, it makes up the pair of additional marks that the Sanskrit phonetic tradition groups apart from the letters proper and calls the ayogavaha, the sounds that do not join. The two marks matter to this atlas for a specific reason: the Tantric traditions that treat the alphabet as a garland of matrika generally reckon fifty, and reaching fifty requires counting both of them alongside the fourteen vowels and the thirty-three consonants, with the retroflex lateral sometimes making up the number in schemes that arrange it differently. This atlas seeds the forty-seven letters and does not seed the two marks as letters, since the tradition itself distinguishes them from letters.

The count of fifty is recorded on each letter as a property of the series, and Andre Padoux's study describes how the schools arrive at it and how their arrangements differ. Editions differ over whether to print the mark wherever the rules call for it or to restore the underlying sound for the reader, so a beginner using two editions side by side will meet the same passage in two shapes. Knowing that the mark stands for something recoverable, rather than for a sound of its own, is what makes that difference intelligible instead of alarming.