Each department of science requires a separate and distinct kind of sight. The astute merchant deciphers at a glance the precise state of the most intricate accounts, in the midst of thousands of seemingly conflicting figures; but of the thousand interesting and wonderful things concerning the little beetle that crosses his path in his country walk, he is incapable of seeing any single particle; while the despised entomologist, whom he has contemptuously observed turning over the stones at the road-side, and peering curiously beneath them, could tell him a tale of wonder, could preach him a sermon upon that tiny type, such as would surely wake up many latent and unsuspected powers in his mind, that would enable him to _see_ wonders where all had previously been blank, and teach him that there are things well worthy of investigation beyond the region of money-making, and the attractive but narrow circle distinguished by the fascinating characters, £ _s._ _d._ Those who cannot _see_ Nature, who cannot see more than an unclean thing in the little creeping beetle, are like one gazing at a carved Egyptian record, who perceives, in the hieroglyphic scarabæus, simply the sculptured figure of a beetle, and no more—they are in a state of “Egyptian darkness” as regards one of the highest and most enchanting fields of human research. But to those who have acquired this rare though easy art, and learned to _see_ Nature, even to a moderate extent (for in that art are an infinite number of degrees and gradations), the aspect of the ocean floor must present an appearance as beautiful and strange, and seemingly as supernatural, as the wildest imagination could depicture. When poets would travel, in their inventive flights, to other floating and revolving worlds than ours, they describe rosy skies, instead of azure, and trees like branching crystals, with jewel-like fruits glittering on every stem. They present us with pictures, in short, in which all the ordinary aspects of our planet are reversed, or metamorphosed, in the region of their invention; but in their most fanciful pictures they do not surpass in strangeness the wonders of the world beneath the sea. On the land, we have, as the ordinary aspect of Nature, the green herbaceous mantle of the earth below the eye, and the azure sky above; while a spectator, standing beneath the water on the ocean floor, would see these features more than reversed: he would see above him a liquid atmosphere of green, and below, an herbage of red or of purple hue, exhibiting strange yet exquisite forms, such as no terrestrial vegetation displays. Roseate shrubs of jointed stone, and arborets of filmy glass, and creatures full of active, energetic life, whose forms are stranger still, both in structure and in appearance; mere worms, whose colours are gorgeous as the tints of the butterfly’s wing, or the peacock’s tail, or the humming-bird’s breast.