The names commonly dedicated to these planes, taking them in order of materiality, rising from the heavier to the finer, are the physical, the astral, the mental or devachanic, the buddhic, and the nirvanic.Greater than this last are 2 others, but they are so far above our present power of concept that for the moment they might be left out of consideration. It ought to be understood that the matter of each of these planes differs from that of the one below it in the same way as, though to a much higher degree than, vapor differs from solid matter.
The astral region which I'm to try to describe is the second of these planes of nature—the next above (or inside) that physical world with which we're all familiar. It has frequently been called the realm of illusion—not that it's itself any more elusive than the physical world, but, as of the extreme un-reliableness of the impressions returned from it by the untrained seer. This is to be accounted for chiefly by two remarkable features of the astral world—first, that a lot of its inhabitants have a fantastic power of changing their forms, and also of casting practically inexhaustible glamour over those with whom they choose to sport; and second, that sight on that plane is a faculty really dissimilar from and much more extended than physical vision.