I have been practicing Taoist internal alchemy methods, I created a crystal of shen (spirit) in my lower dan tien which fills my body with light.
The same as external alchemists cook materials in a cauldren, I cooked jing and chi in the cauldren of my dan tien to create the crystal; the sexual glands are the 'stove' which heats the cauldren.
It took me two days to do, that night I dreamed about the five elements (I had not been thinking about the five elements before the dream).