field" and it is located about an inch down from navel. Shen or "spiritual energy" is seated in the Middle Dantian, which is the Heart. During the Han dynasty and after, Neidan and Daoist martial arts gradually merged into one, becoming Neijia martial arts. Famous Taijiquan masters who practiced Neijia include Wu Tunan (吳圖南) and Chen Weiming (陳微明). Associated risks When ingested, these compounds did not always result in the desired outcome. Many individuals died or had psychological difficulties after taking certain elixirs. However, the loss of life may not have seemed a large risk, when compared with the promise of the afterlife. Although these elixirs were lethal or dangerous, there is some contention that these individuals were not ignorant of the fatality of some of the materials they were ingesting. There were certain grades of immortality, so if the practiced alchemist died, the level of immortality they achieved was determined by their corpse. If their corpse was sweet-smelling, it was said that they had achieved immortality in an ephemeral state. Likewise, if their corpse disappeared, leaving behind only the clothes, such as in the death of an adept named Ko Hung, this was another form of immortality known as shih chieh hsien (corpse-free immortals) (Cooper, 14). Conception of medicine Medicines can be used to heal ailments on the exterior or interior of the body, to control the ageing of the body, or even to prevent death. The term medicine and elixir are virtually interchangeable because of the array of ailments they can influence. The difference between defining an elixir from a medicine was that many medicines were composed mainly of all natural products like herbs and animal products. Never the animals themselves, only their products, which could consist of dung or fur. Although metal compounds are more potent when curing ailments, herbs were used because they were easier to combine and more abundantly available. To make medicines one would use ingredients like: Kolo nuts, which would be used in famous longevity pills like "Fo-Ti-Ti"; Asparagus, which was used because it was known to increase strength; sesame, which prevents senility; and pine which has over 300 different uses. (Cooper, 1990. Pg. 62) Mushrooms were and still are very popular, they are known as the "magic fungus" (Ganoderma) and have thousands of purposes within Chinese alchemy. Practitioners Chinese women alchemists With the rise of alchemy in Chinese civilization, alchemy began to