70. The ं anusvāra, ṅ or ṁ, is a nasal sound lacking that closure of the organs which is required to make a nasal mute or contact-sound (36); in its utterance there is nasal resonance along with some degree of openness of the mouth.
71. There is discordance of opinion among both the Hindu phonetists and their modern European successors respecting the real character of this element; hence a little detail is necessary here with regard to its occurrence and their views of it.
a. Certain nasals in Sanskrit are of servile character, always to be assimilated to a following consonant, of whatever character that may be. Such are final m in sentence-combination (213), the penultimate nasal of a root, and a nasal of increment (255) in general. If one of these nasals stands before a contact-letter or mute, it becomes a nasal mute corresponding the the latter — that is, a nasal utterance in the same position of the mouth-organs which gives the succeeding mute. If, on the other hand, the following consonant does not involve a contact (being a semivowel or spirant), the nasal element is also without contact: it is a nasal utterance with unclosed mouth-organs. The question is, now, whether this nasal utterance becomes merely a nasal infection of the preceding vowel, turning it into a nasal vowel (as in French on, en, un, etc., by reason of a similar loss of a nasal mute); or whether it is an element of more individual character, having place between the vowel and the consonant; or, once more, whether it is sometimes the one thing and sometimes the other. The opinions of the Prātiçākhyas and Pāṇini are briefly as follows:
b. The Atharva-Prātiçākhya holds that the result is everywhere a nasalized vowel, except when n or m is assimilated to a following l; in that case, the n or m becomes a nasal l: that is, the nasal utterance is made in the l-position, and has a perceptible l-character.
c. The other Prātiçākhyas teach a similar conversion into a nasal counterpart to the semivowel, or a nasal semivowel, before y and l and v (not before r also). In most of the other cases where the Atharva-Prātiçākhya acknowledges a nasal vowel — namely, before r and the spirants — the others teach the intervention after the vowel of a distinct nasal element, called the anusvāra after-tone.
d. Of the nature of this nasal afterpiece to the vowel no intelligibly clear account is given. It is said (RPr.) to be either vowel or consonant; it is declared (RPr., VPr.) to be made with the nose alone, or (TPr.) to be nasal like the nasal mutes; it is held by some (RPr.) to be the sonant tone of the nasal mutes; in its formation, as in that of the vowel and spirant, there is (RPr.) no contact. As to its quantity, see further on.
e. There are, however, certain cases and classes of cases where these other authorities also acknowledge a nasal vowel. So, especially, wherever