"The subtlest forms of matter, as commonly known, are the imponderables--light, heat, magnetism, and electricity. I had concluded that these were manifestations of some still subtler form, and that this was _life_, beyond which lay the ethereal elements (called _principles_) of mind and soul--soul being ultimate and eternal. To demonstrate this I resolved to descend as far as possible into the depths of the sea, and examine the beings which dwelt in the remotest darkness. The conical shape of my island allowed me to descend within its shelving interior, and yet sustain no great atmospheric pressure. I selected a sturgeon, whose body was so powerfully plated that he could not be crushed, and his long-pointed shape gave him great facility for penetrating dense waters. I attached a phosphorescent light to his caudal, that I might not lose him in the gloom, and he preceded me along the sloping interior. We passed the foundations of my court, bade adieu to the deep-swimming hydras, left the profoundest polypi behind, and came at length to uninhabited regions, three thousand fathoms below the surface. My pioneer here suffered great inconvenience, and only by the most vigorous efforts was able to progress at all. The blackness was literally tangible, and our lantern, at most, only 'darkness visible.' By threat and persuasion I forced him forward, hardly able to make headway myself. He swept the almost solid element with his powerful tail, depressed his sharp snout, sucked a long breath, and we darted forward simultaneously. There was a cracking as of bones forced together, and my cranium seemed to split. We shot out of the density into lighter water, and the momentum carried us fifty fathoms beyond! "We had passed out of the limit of solar attraction, and were being drawn toward the centre of the earth! "Before, we had been descending; now, we were rising. The fluid grew rarer and warmer as we proceeded, the darkness more luminous, and at last we became visible to each other, swimming in a ruby and transparent liquid, unlike any aspect or part of our native domain. The fluid became so rare finally, that the sturgeon was unable to go farther, kept down by his superior gravity. Some lights glimmering above us, and some mysterious sounds alarming him, he turned and fled. I was left alone. "I reached the surface of this peaceful sea. A scene lay before me more beautiful than any wonder of the deep. I knew that I was among immortals, and that this was 'Happy Archipelago'!