Fancy not, reader, that this tumult of images, illustrative or allusive, moves under any impulse or purpose of mirth. It is but the coruscation of a restless understanding, often made ten times more so by irritation of the nerves, such as you will first learn to comprehend (its _how_ and its _why_) some stage or two ahead. The image, the memorial, the record, which for me is derived from a palimpsest, as to one great fact in our human being, and which immediately I will show you, is but too repellent of laughter; or, even if laughter _had_ been possible, it would have been such laughter as often times is thrown off from the fields of ocean[10]--laughter that hides, or that seems to evade mustering tumult; foam-bells that weave garlands of phosphoric radiance for one moment round the eddies of gleaming abysses; mimicries of earth-born flowers that for the eye raise phantoms of gaiety, as oftentimes for the ear they raise echoes of fugitive laughter, mixing with the ravings and choir-voices of an angry sea. What else than a natural and mighty palimpsest is the human brain? Such a palimpsest is my brain; such a palimpsest, O reader! is yours. Everlasting layers of ideas, images, feelings, have fallen upon your brain softly as light. Each succession has seemed to bury all that went before. And yet in reality not one has been extinguished. And if, in the vellum palimpsest, lying amongst the other _diplomata_ of human archives or libraries, there is any thing fantastic or which moves to laughter, as oftentimes there is in the grotesque collisions of those successive themes, having no natural connexion, which by pure accident have consecutively occupied the roll, yet, in our own heaven-created palimpsest, the deep memorial palimpsest of the brain, there are not and cannot be such incoherencies. The fleeting accidents of a man's life, and its external shows, may indeed be irrelate and incongruous; but the organizing principles which fuse into harmony, and gather about fixed predetermined centres, whatever heterogeneous elements life may have accumulated from without, will not permit the grandeur of human unity greatly to be violated, or its ultimate repose to be troubled in the retrospect from dying moments, or from other great convulsions.