In the elderly, who experience dry mouth and seminal emission or diarrhea during night sleep, one may collect their own urine and drink a cup occasionally to prolong life. This utilizes the interaction between the Kan (Kidney Water/Yin) and Li (Heart Fire/Yang) within one's own body.
Shihuang (Sulfur, processed, 1 jin) Qingdai (Realgar Blue/Fly-dust, 1 liang 6 qian)
Make pills with Shihuang (Sulfur), and coat them with Qingdai (Realgar Blue).
For the elderly suffering from abundant internal cold-phlegm, taking this formula can eliminate disease and extend longevity.
Shihuang (Sulfur) is the essence of fire; humans cannot survive without this fire, hence it is used to benefit the Fire (Mingmen Fire). Using Qingdai (Realgar Blue) as a coating serves to restrain its drying and irritating nature.
For those of old age and weak constitution, wood, stone, and mineral drugs cannot adequately nourish Qi and Blood. Therefore, substances derived from blood and Qi are used in medicine for harmonization, to be taken alongside diet. The principle is that similar things attract each other, making nourishment easier. Even the saying that those over seventy must eat meat to feel full reflects this same idea.