Take water for example. O1 (one) and H2 (two), that represents a chemical compound. It is most abundant, and is by far the most essential, in the formation of organic life. Air, water, fire, are represented by the four elements C H N O. Every power, every force known to man is dependent upon these. Every kind of life is made up of these. Of every phenomenon manifested by nature, whatever the display may be or where it may occur, these elements are the fundamental basis. Protoplasm, which is acknowledged to be the base of physical life, is nothing more than a homogeneous mass of albuminous matter which is composed of C H N O--with a greater or less quantity of each of these elements. These elements enter into the formation of all gases, fluids, and solids. They are invisible at one time and visible at another. Without taste or color or odor in a free state, or even in combination, they assume taste, color, and odor when the elements combine in certain proportions. They become either harmless or poisonous; create, maintain, or destroy life. Oxygen is a tasteless, colorless, and inodorous gas. Hydrogen is a colorless, tasteless, and inodorous gas. Nitrogen is destitute of color, taste, or odor. Carbon is a solid but becomes gaseous in combination with either Oxygen or Hydrogen. The diamond is one of the most remarkable substances known. It is always distinctly crystallized, often quite transparent and colorless, now and then having a shade of yellow, pink, or blue. Carbon is also found as graphite or plumbago. It constitutes a large proportion of all organic structures, animal and vegetable. Pure carbon, diamond, is the hardest substance known. In combination with Oxygen and Hydrogen it forms the softest of living matter, protoplasm. In combination with Oxygen it is poisonous to all animal life, and beneficial to vegetable life. Combined with Hydrogen, it forms the gas we burn, and is destructive to animal life. It is the food-maker in the plant, and it is the food-provider for the animal. It is the combustive agent in nature, in vegetables and in animals. From a thunderstorm to a flickering flame of a candle, carbon displays its power. From the smallest and lowliest aquatic vegetable cell to the highest animal cell tissue, it is the important solidifying, heat-giving element. These elements when free have neither color, odor, nor taste. Combined, however, they acquire odor, taste, and color. O and N, the atmosphere, has no color, taste, or odor. O and H, water, has no color, taste, or odor. N and H, ammonia, has color, taste, and odor. O and C is given off by animals, taken in by vegetables--carbonic acid. C and H, the gas, has taste, odor, and color. N and O produce a gas--laughing gas. Any two of these elements may combine in the form of a gas, a liquid, or a solid. And any one may combine with any other element known and form a substance, a molecule. O combines with all the elements known. H    ,,     ,,  many.