It seems to be the fundamental rule running through Nature that periods of rest or quiescence alternate with periods of activity, complete or incomplete. In this great world we know that light and darkness, summer and winter, rain and dryness alternate; and in our bodies respiration, heart beats and mental activity alternate with periods of rest. Joy and sorrow, hope and fear, exaltation and depression, love and hate alternate.
When we turn to the field of therapeutics, we can think of many conditions that require some active and immediate attention, such as injuries resulting from accidents; but in all cases—surgical or medical—there comes a period of rest. Following a gallbladder operation, removal of the tonsils or the appendix, the setting of a fracture, the removal of the prostate gland or of a cataract, a period of rest follows; so with therapeutics of medicine, such as drugs, baths and massage, administration