The chief processes of Hathayoga are asana and prayama. By its numerous asanas or fixed postures it first cures the body of that restlessness which is a sign of its inability to contain without working them off in action and movement the vital forces poured into it from the universal Life-Ocean, gives to it an extraordinary health, force and suppleness and seeks to liberate it from the habits by which it is subjected to ordinary physical Nature and kept within the narrow bounds of her normal operations. In the ancient tradition of Hathayoga it has always been supposed that this conquest could be pushed so far even as to conquer to a great extent the force of gravitation. By various subsidiary but elaborate processes the Hathayogin next contrives to keep the body free from all impurities and the nervous system unclogged for those exercises of respiration which are his most important instruments. These are called pranayama, the control of the breath or vital power; for breathing is the chief physical functioning of the vital forces. Pranayama, for the Hathayogin, serves a double purpose. First, it completes the perfection of the body. The vitality is liberated from many of the ordinary necessities of physical Nature; robust health, prolonged youth, often an extraordinary longevity are attained. On the other hand, Pranayama awakens the coiled-up serpent of the Pranic dynamism in the vital sheath and opens to the Yogin fields of consciousness, ranges of experience, abnormal faculties denied to the ordinary human life while it puissantly intensifies such normal powers and faculties as he already possesses.