physical rest. This is granted in that loss of consciousness, regularly recurrent in animal life, which is called sleep.
All during life each component part of the body in the very act of living produces poison within itself. When toxins accumulate faster than they are eliminated, as occurs when no interval of rest is granted, fatigue is felt, and fatigue is only another name for toxic infection. A normal amount of labor is easily cared for by the muscular system, but excess work brings disaster. If action and rest are so regulated that the cells may give off their waste products at a rate to keep pace with new formations, muscle, and nerve tissue as well, will always be in position to liberate energy on demand.
From the time of birth until death, the organs of the human body function continuously. On the other hand, in the vegetable kingdom the plant maintains and conserves life by added growth from year to year. The vital parts of the plant are re-created and their predecessors become mere physical supports corresponding to the bony framework in man. The power resident in the tree of producing new equipment annually is denied to humanity, not by nature, but because of
