Siddham Au 𑖍

Au is the second strengthening grade of u, the counterpart of ai on the other side of the vowel system, and with it the vowel section of the syllabary closes. The four long vowels that end the series therefore form two matched pairs rather than a list of remainders: e and ai built up from i, o and au built up from u, each pair one step and then two.

In the vocabulary the vowel is not common, but where it occurs it is doing recognisable work. The second grade marks words derived from other words, so a term beginning with this vowel is usually a derivative naming something belonging to, descended from or characteristic of whatever its base names. Reading Sanskrit is in large part the habit of noticing such signals, and this letter is one of the loudest of them.

In metre it counts as heavy, like every long vowel. On the page it follows the ordinary rule: written in full only where a word opens on it, and elsewhere as a mark attached to the preceding consonant. With this letter the reciter of the table crosses from the vowels to the consonants, and the two sections are learned, counted and named as distinct halves of one order.

The independent letter is rare in running text and most readers meet it first in the chart rather than on a page. The dependent mark is another matter, and turns up wherever the second strengthening grade is used, which in a text discussing schools, doctrines and derived qualities is frequently. The two forms of one vowel can have very different frequencies.

Forty-seven letters do not account for everything written in Siddham. A set of marks sits alongside them, none of which is counted among the letters and all of which are needed to write the language. Two are sounds in their own right. The nasal mark, written above the syllable, indicates a nasal quality carried by the vowel; the mark written after it, a pair of dots, indicates a breath released at the end of a word. Both appear constantly, and both are essential to the seed syllables of East Asian esoteric Buddhism, where a great many of the syllables are a letter plus one of these marks rather than a bare letter.

A third mark does the opposite job. It cancels the vowel that a consonant sign automatically carries, so that the consonant can close a syllable with nothing after it. Without it an abugida cannot write a word ending in a consonant at all, and Sanskrit has a great many.

The distinction between letters and marks matters for anything that counts. A reference work listing the Siddham characters may be counting the letters of the traditional order, or the letters plus the dependent vowel signs, or everything an encoding needs in order to reproduce a manuscript. The three numbers are different and each is right for its question. What the tradition itself names as the syllabary is the forty-seven.