Chapter III. The Visible and the Invisible World The Chemical Region. If one who is capable of consciously using his spiritual body with the same facility that we now use our physical vehicles should glide away from the earth into interplanetary space, the earth and the various other planets of our solar system would appear to him to be composed of three kinds of matter, roughly speaking. The densest matter, which is our visible earth, would appear to him as being the center of the ball as the yolk is in the center of an egg. Around that nucleus he would observe a finer grade of matter similarly disposed in relation to the central mass, as the white of the egg is disposed outside the yolk. Upon a little closer investigation he would also discover that this second kind of substance permeates the solid earth to the very center, even as the blood percolates through the more solid parts of our flesh. Outside both of these mingling layers of matter he would observe a still finer, third layer corresponding to the shell of the egg, except that this third layer is the finest most subtile of the three grades of matter, and that it inter-penetrates both of the two inner layers. As already said, the central mass, spiritually seen, is our visible world, composed of solids, liquids and gases. They constitute the earth, its atmosphere, and also the ether, of which physical science speaks hypothetically as permeating the atomic substance of all chemical elements. The second layer of matter is called the Desire World and the outermost layer is called the World of Thought. [055]