It is said (1) that there are 3Â½ crores of nadis in the human body, of which some are gross and some are subtle. Nadi means a nerve or artery in the ordinary sense; but all the nadis of which the books on Yoga (2) speak are not of this physical character, but are subtle channels of energy.
Of these nadis, the principal are fourteen; and of these fourteen, ida, pingala and susumna are the chief and again, of these three, susumna is the greatest, and to it all others are subordinate. Susumna is in the hollow of the meru in the cerebro-spinal axis. (3) It extends from the Muladhara lotus, the Tattvik earth centre, (4) to the cerebral region. Susurnna is in the form of Fire (vahni-svarupa), and has within it the vajrini-nadi in the form of the sun (surya-svarupa.). Within the latter is the pale nectar-dropping citra, or citrini nadi, which is also called Brahma-nadi, in the form of the moon (candra-svarupa). Susumna is thus triguna,
The various lotuses in the different Cakras of the body (vide post) are all suspended from the citra-nadi, the cakras being described as knots in the nadi, which is as thin as the thousandth part of a hair. Outside the meru and on each side of susumna are the nadis ida and pingala. Ida is on the left side, and coiling round susumna, has its exit in the left nostril. Pingala is on the right, and similarly coiling, enters the right nostril. The susumna, interlacing ida and pingala and the ajna-cakra round which they pass, thus form a representation of the caduceus of Mercury.
Ida is of a pale colour, is moon-like (candra-svarupa), and contains nectar. Pingala is red, and is sun-like (suryasvarupa), containing “venom,” the fluid of mortality. These three “rivers,” which are united at the ajnacakra, flow separately from that point, and for this reason the ajnacakra is called mukta triveni. The muladhara is called Yukta (united) triveni, since it is the meeting-place of the three nadis which are also called Ganga (Ida), Yamuna (Pingala), and Sarasvati (susumna), after the three sacred rivers of India. The opening at the end of the susumna in the muladhara is called brahma-dvara, which is closed by the coils of the sleeping Devi Kundalini.
There are six cakras, or dynamic Tattvik centres, in the body – viz., the muladhara, svadhisthana, manipura, anahata, visuddha, and ajna – which are described in the following notes. Over all these is the thousand-petalled lotus (sahasrara-padma).
1. Nadi-vijnana (chap. i, verses 4 and 5).
2. Sat-cakra-nirupana (commentary on verse I), quoting from Bhuta suddhi-Tantra. speaks of 72000 nadis (see also Nilruttara-Tantra, Pranatosini, p. 35), and the S’iva-samhita (2, 13) of three lacs and 50,000.
3. It has been thought, on the authority of the Tantra-cuda-mani that susumna is outside meru; but this is not so, as the Author of the Sat-cakranirnpana points out (verse 2). Ida and Pingala are outside the meru; the quoted passage in Nigama-tattva-sara referring to susumna, vajra and citrini.
4. TheTattvas of “earth,” water,” fire,” air,” and “ether,” are not to be identified with the so-called popular “elements” of those names.