What is the spirit? where is the center of its existence? and what is its function? What is the soul? where is the center of its existence? and what is its function? what is the thought? where does it exist? and what is its function? What is the mind? where is its center? and what is its function? What is its relation with? and what are the relations of the above-mentioned items to each other?. Researches about the sources of spring water in the world