No doubt it is between the stable and the unstable condition of the molecules of matter that life is born. The static condition to which all things tend is death. Matter in an unstable condition tends either to explode or to grow or to disintegrate. So that an explosion bears some analogy to life, only it is quickly over and the static state of the elements is restored. Life is an infinitely slower explosion, or a prolonged explosion, during which some matter of the organism is being constantly burned up, and thus returned to a state of inorganic repose, while new matter is taken in and kindled and consumed by the fires of life. One can visualize all this and make it tangible to the intellect. Get your fire of life started and all is easy, but how to start it is the rub. Get your explosive compound, and something must break the deadlock of the elements before it will explode. So in life, what is it that sets up this slow gentle explosion that makes the machinery of our vital economies go--that draws new matter into the vortex and casts the used-up material out--in short, that creates and keeps up the unstable condition, the seesaw upon which life depends? To enable the mind to grasp it we have to invent or posit some principle, call it the vital force, as so many have done and still do, or call it molecular force, as Tyndall does, or the power of God, as our orthodox brethren do, it matters not. We are on the border-land between the knowable and the unknowable, where the mind can take no further step. There is no life without carbon and oxygen, hydrogen and nitrogen, but there is a world of these elements without life. What must be added to them to set up the reaction we call life? Nothing that chemistry can disclose. New tendencies and activities are set up among these elements, but the elements themselves are not changed; oxygen is still oxygen and carbon still carbon, yet behold the wonder of their new workmanship under the tutelage of life! Life only appears when the stable passes into the unstable, yet this change takes place all about us in our laboratories, and no life appears. We can send an electric spark through a room full of oxygen and hydrogen gas, and with a tremendous explosion we have water--an element of life, but not life. Some of the elements seem nearer life than others. Water is near life; heat, light, the colloid state are near life; osmosis, oxidation, chemical reactions are near life; the ashes of inorganic bodies are nearer life than the same minerals in the rocks and soil; but none of these things is life.