"He who knows Prana knows Vedas" is the important declaration of the Srutis. You will find in Vedanta Sutras: "For the same reason, breath is Brahman." Prana is the sum total of all energy that is manifest in the universe. It is the sum total of all the forces in nature. It is the sum total of all latent forces and powers which are hidden in men and which lie everywhere around us. Heat, light, electricity, magnetism are the manifestations of Prana. All forces, all powers and Prana spring from the fountain or common source, 'Atman'. All physical forces and all mental forces come under the category 'Prana'. It is the force on every plane of being, from the highest to the lowest. Whatever moves or works or has life, is but an expression or manifestation of Prana. Akasa or ether also is an expression of Prana. The Prana is related to mind and through mind to will, and through will to the individual soul, and through this to the Supreme Being. If you know how to control the little waves of Prana working through the mind, then the secret of subjugating universal Prana will be known to you. The Yogi who becomes an expert in the knowledge of this secret, will have no fear from any power, because he has mastery over all the manifestations of powers in the universe. What is commonly known as power of personality is nothing more than being successful in life, more influential and fascinating than others. It is all due to the power of this Prana. Such people manipulate everyday, unconsciously of course, the same influence which the Yogi uses consciously by the command of his will. There are others who by chance tumble unaware of this Prana and use it for lower purposes under false names. This working of Prana is seen in the systolic and diastolic actions of the heart, when it pumps the blood into arteries in the action of inspiration and expiration during the course of breathing; in the digestion of food; in the excretion of urine and faecal matter; in the manufacture of semen, chyle, chyme, gastric juice, bile, intestinal juice, saliva; in closing and opening of the eyelids, in walking, playing, running, talking, thinking, reasoning, feeling and willing. Prana is the link between the astral and physical body. When the slender thread-link Prana is cut off, the astral body separates from the physical body. Death takes place. The Prana that was working in the physical body is withdrawn into the astral body.
This Prana remains in a subtle, motionless, unmanifested, undifferentiated state during the cosmic Pralaya. When the vibration is set up, Prana moves and acts upon Akasa, and brings forth the various forms. The macrocosm (Brahmanda) and microcosm (Pindanda) are combinations of Prana (energy) and Akasa (matter).
That which moves the steam-engine of a train and a steamer, that which makes the aeroplanes fly in air, that which causes the motion of the breath in lungs, that which is the very life of this breath itself, is Prana. I believe, you have now a comprehensive understanding of the term Prana about which you had a very vague conception in the beginning.
By controlling the act of breathing you can efficiently control all the various motions in the body and the different nerve-currents that are running through the body. You can easily and quickly control and develop body, mind and soul through breath control or the control of Prana. It is through Pranayama that you can control your circumstances and character, and can consciously harmonise the individual life with the cosmic life.
The breath, directed by thought under the control of the will, is a vitalising, regenerating force which you can utilise consciously for self-development; for healing many incurable diseases in your system; for healing others and for other various useful purposes.
It is within your easy reach at every moment of your life. Use it judiciously. Many Yogins of yore, like Sri Jnanadeva, Trailinga Swami, Ramalinga Swami and others, had utilised this breath, this force, the Prana, in a variety of ways. You can also do so, if you practise Pranayama by prescribed breathing exercises. It is Prana that you are breathing rather than the atmospheric air. Inhale slowly and steadily with a concentrated mind. Retain it as long as you can do it comfortably. Then exhale slowly. There should be no strain in any stage of Pranayama. Realise the occult inner life-powers which underlie the breath. Become a Yogi and radiate joy, light and power all around you.
Pranavadins or Hatha Yogins consider that Prana Tattva is superior to Manas Tattva, the mind principle. They say, Prana is present even when the mind is absent during sleep. Hence Prana plays a more vital part than the mind. If you go through the parables in Kaushitaki and Chhandogya Upanishads, when all the Indriyas, mind and Prana fight amongst themselves as to their superiority, you will find that Prana is regarded as the highest of all. Prana is the oldest, for it starts its functioning from the very moment the child is conceived. On the contrary, the organs of hearing, etc., begin to function only when their special abodes, viz., the ears, etc., are formed. Prana is called Jyestha and Sreshtha (oldest and best) in Upanishads. It is through the vibrations of psychic Prana that the life of the mind, Sankalpa or thinking, is kept up and thought is produced. You see, hear, talk, sense, think, feel, will, know, etc., through the help of Prana and therefore Srutis declare: "Prana is Brahman."
SEAT OF PRANA
The seat of Prana is heart. Though the Antahkarana is one, yet it assumes four forms, viz., (i) Manas, (ii) Buddhi, (iii) Chitta and (iv) Ahamkara, according to the different functions it performs. Likewise, though Prana is one, it assumes five forms viz., (1) Prana, (2) Apana, (3) Samana, (4) Udana and (5) Vyana, according to the different functions it performs. This is termed as Vritti Bheda. The principal Prana is called Mukhya Prana. The Prana, joined with Ahamkara, lives in the heart. Of these five, Prana and Apana are the chief agents.
The seat of Prana is the heart; of Apana, the anus; of Samana, the region of the navel; of Udana, the throat; while Vyana is all-pervading. It moves all over the body.
SUB-PRANAS AND THEIR FUNCTIONS
Naga, Kurma, Krikara, Devadatta and Dhananjaya are the five sub-Pranas.
The function of Prana is respiration; Apana does excretion; Samana performs digestion; Udana does deglutition (swallowing of the food). It takes the Jiva to sleep. It separates the astral body from the physical body at the time of death; Vyana performs circulation of blood.
Naga does eructation and hiccup. Kurma performs the function of opening the eyes. Krikara induces hunger and thirst. Devadatta does yawning. Dhananjaya causes decomposition of the body after death. That man is never reborn, whenever he may die, whose breath goes out of the head, after piercing the Brahmarandhra.
THE COLOUR OF PRANAS
Prana is said to be of the colour of blood, red gem or coral. Apana, which is in the middle, is of the colour of Indragopa (an insect of white or red colour). Samana is of the colour between that of pure milk or crystal or of oily and shining colour, i.e., of something between both Prana and Apana. Udana is of Apandura (pale white) colour and that of Vyana resembles the colour of archil (or that of ray of light).
THE LENGTH OF THE AIR-CURRENTS
This body of Vayu is 96 digits (6 feet) in length as a standard. The ordinary length of the air-current, when exhaled is 12 digits (9 inches). In singing, its length becomes 16 digits (1 foot), in eating it comes to 20 digits (15 inches), in sleeping 30 digits (22 inches), in copulation 36 digits (27 inches) and in doing physical exercise it is much more than that. By decreasing the natural length of the expired air-currents (from 9 inches), life is prolonged and by increasing the current, duration of life is decreased.
THE CENTRING OF THE PRANA
Inhaling the Prana from outside, filling the stomach with it, centre the Prana with the mind, in the middle of the navel, at the tip of the nose, and at the toes, during the 'Sandhyas' (sunrise and sunset) or at all times. Thus the Yogi is freed from all diseases and fatigues. By centring this Prana at the tip of the nose he obtains mastery over the elements of the air; by centring at the middle of his navel, all diseases are destroyed; by centring at the toes, his body becomes light. He who drinks air through the tongue destroys his fatigue, thirst and many other diseases. For him who drinks the air with his mouth, during the two Sandhyas and the last two hours of the night, within three months, the auspicious Sarasvati (Goddess of speech) is present in his Vak (speech), i.e., he becomes eloquent and learned. In six months he is free from all diseases. Drawing the air at the root of the tongue, the wise man thus drinking nectar enjoys all prosperity.