THE CULT OF JOY 311 



secretions." Emotion may influence the produc- 

 tion of adrenalin by the core of the adrenal glands, 

 and a slight increase in this powerful substance 

 constricts the smaller blood-vessels, raises the blood 

 pressure, excites and freshens the muscles, increases 

 the sugar-content of the blood, and so on. Good 

 news, psychical if anything is, may set in motion 

 a series of physico-chemical and vital processes, 

 complex beyond the ken of the wisest. And the 

 cheerful man, who cultivates the habit of happiness, 

 finding reasons for rejoicing in the sunshine and the 

 stars, in flowers and birds, in works of art and the 

 faces of his friends, will have his " joy-reward " or 

 euphoria added unto him unless he is fool enough 

 to pursue it. 



The second line of argument refers to the cir- 

 culation. Wordsworth was a better physiologist 

 than he knew when he spoke of his heart leaping 

 up at the sight of the rainbow, or filling with 

 pleasure and dancing at the recollection of the 

 daffodils. He may not have known much about 

 the distribution of the pneumogastric nerve, but 

 he knew of the influence of joy on the circulation. 

 Experiments have been made by prevaricating 

 physiologists who take the pulses of whole classes 

 of students, give them milk-sugar pills, tell them 

 that they have taken heart stimulants or heart 

 depressants, and observe after a time the change 

 in the pulse rates. Many of the hearts beat faster 

 after the imaginary stimulant, and slower after 

 the imaginary depressant, but what is more inter- 



