The number placed against each element indicates the quantity of each one requisite, or found, in the composition, or chemical combination, of the substance indicated.
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.