What we observe in lightning is really an instantaneous execution of a process which runs its course continually in the atmosphere, quietly and unnoticed. It is the process by which water reverts from the imponderable to the ponderable condition, after having been converted to the former through levity set in action by the sun (as usually happens in a high degree just before a thunderstorm). We form a true picture of the course of a storm if we say that nature enables us to witness a sublime display of the sudden bringing to birth of matter in earthbound form. What falls to the ground as rain (or hail) is substantially identical with what was perceptible to the eye, a moment before, as a majestic light-phenomenon. The accompanying electrical occurrence is the appropriate counter-event at nature's lower boundary. Since the two form part of a larger whole they necessarily occur together; but the electrical occurrence must not be identified with the event in the heavens. The reason for their conjunction will become clear later, when we shall show how electrical polarity arises from the polarity between gravity and levity.