156 THE CONTROL OF LIFE 



long ago, " He that is of a merry heart hath a con- 

 tinual feast," and " A merry heart is the life of the 

 flesh." The researches of Pavlov, Cannon, Carlson, 

 and Crile have shown that pleasant emotions favour 

 the secretion of the digestive juices, the rhythmic 

 movements of the food-canal, and the absorption 

 of the aliment. Contrariwise, unpleasant emotional 

 disturbance and worry of all sorts hinder digestion. 

 Good news, psychical if anything is, may set in motion 

 a series of vital processes, complex beyond the ken 

 of the wisest. What is true of digestion is true of 

 the circulation. Wordsworth was a better physiolo- 

 gist than he knew when he spoke of his heart leap- 

 ing up at the sight of the rainbow and filling with 

 pleasure and dancing at the recollection of the daf- 

 fodils by the lakeside. There are facts which point 

 to the conclusion that a gladsome mind increases the 

 efficiency of the nervous system. Good tidings will 

 invigorate the flagging energies of a band of explorers ; 

 an unexpected visit will change a wearied homesick 

 child, as if by magic, into a dancing gladsome elf; 

 a religious joy enables men and women to transcend 

 the limits of our frail humanity. How it operates is 

 not very clear, but emotion has its physical accom- 

 paniment in motions visible and invisible throughout 

 the body. Somehow the oil of joy, as the Scriptures 

 call it, makes the limbs more supple and the face to 

 shine. 



It goes without saying that forced cheerfulness is a 

 horror, but the persistent will to be glad, if worthily satis- 



