Inner Alchemy is the big payoff for the hard work of learning and practicing the exercises that are listed in the book thus far. The way I understand and teach inner alchemy is a process of absorbing a variety of energies from nature and blending those energies with our own. The result of this is to grow closer to the pattern of nature itself. The pattern of nature has its ups and downs, its cycles, its violent upheavals, and quiet periods of seeming nothingness. However, in spite of these fluctuations, the Taoist philosophy is that nature is in balance overall.
In one level of Taoist inner alchemy, that of Water and Fire, the Primal Fire and Primal Water or Inner Male (Yang) and Inner Female (Yin) are blended together in the lower abdomen. The imagery here is similar to that of a metal pot of boiling water above a fire, sitting on the earth. In this image, all five elements are involved, the wood feeding the fire, the metal holding the water, and all are resting on the earth. This meditation is the next level of the Fusion practice and the meditation is more dynamic. The process creates a healing steam that can flow or be guided through the channels of the body to rejuvenate organs, glands, bones, and vessels.
Tao Yin offers many practices that nourish the hips and spine. By performing squatting, knee raises, and massaging the spine, (through gentle lying movements on the earth), the practitioner learns subtle body awareness. The laying down and sitting down allows one to be comfortable and experience the movement of energy without distractions. Much like a baby becomes accustomed to its environment without the worries of crawling or walking.