Iodine derives its name from iodos, a Greek word signifying violet-colored; but the transcendent beauty of the color of its vapor requires further elucidation than simply saying that it has a violet hue. If a little iodine be placed on a hot tile, it rises into a magnificent dense vapor, fit for the last scene of a theatrical representation. This remarkable substance was discovered by accident about forty years ago. At that period chemical philosophy was in great repute, owing principally to the brilliant discoveries of Sir Humphrey Davy. So singular a substance as iodine was to Davy a source of infinite pleasure. He studied its nature and properties with the fondness and zeal of a child at a Puzzle-map. His great aim was to prove its compound nature: but in this he failed; and to this day it is believed to be one of the primitive elements of the world we live in. Iodine is found in almost every natural substance with which we are acquainted, although in very minute portions. The sea furnishes an inexhaustible supply of iodine: all the fish, the shells, the sponges, and weeds of the ocean, yield it in passing through the chemical sieve. Whatever be the food of sea-weeds, it is certain that iodine forms a portion of their daily banquet; and to these beautiful plants we turn when iodine is to be manufactured for commercial purposes. The weeds cast up by the boiling surf upon the desolate shores of the sea-islands, would at first sight appear among the most useless things in the world; but they are not; their mission is fulfilled; they have drawn the iodine from the briny wave and are ready to yield it up for the benefit and happiness of man. The inhabitants of the Tyrol are subject to a very painful disease, called goitre or cretinism-; for this malady iodine is a perfect cure.
Go, and have your portrait painted as you are. Photography tells the whole truth without flattery; and the colors used in the process are only silver and iodine.—Septimus Piesse.