228 Human Pkvsiology. 



arteries for supplies of blood to furnish new matter. The heart 

 and arteries and whole blood-forming organism are strength- 

 ened by this exercise. Food is needed for blood, and there is 

 increase of appetite and digestive power ; the blood is thrown 

 with a stronger current into the lungs, and the muscles of the 

 chest and the diaphragm act with more vigour to increase the 

 respiration. The chest expands, the lungs enlarge, the brain 

 is furnished with more blood and better blood ; good blood and 

 nerves produce more perfect secretions, and the whole man 

 body, brain, soul, and spirit is filled with a higher, purer, 

 and more vigorous life. 



In the opposite process, laziness leads to disease and stupi- 

 dity ; want of bodily exercise causes a languid action of the 

 heart, poor blood, loss of appetite, dyspepsia, obesity, narrow 

 chest, feeble respiration, imperfect secretions and excretions, 

 retention of impurities in the body, and thence a train of 

 diseases. 



The condition of life is use. " Rust consumes faster than 

 labour wears." This is said of metals; but it applies with ten- 

 fold force to the human organism. In idleness the body falls 

 into languor, disease, decay, and the mind into imbecility. The 

 musician out of practice cannot play men forget languages 

 and sciences. To be good we must do good. We need the 

 daily exercise of the highest theological virtues. To keep us 

 up to our best life we need every day to exercise a wide range 

 of our moral, mental, and physical faculties. Every day we 

 should try to learn and do something which will advance us to 

 a higher level of life. In this requirement, and in this power 

 of progress, we differ from the lower animals. 



Happily the natural tendencies of childhood are to an abun- 

 dance of vigorous exercise. What a wonderful intellectual and 

 muscular activity is displayed by children from a year old 

 in play. The monotony of most kinds of labour may tire and 

 disgust them, but they can play from morning till night, and 



