622 THE CONTROL OF LIFE: 



of Petrograd, Prof. Ivan Petrovich Pavlov, who was 

 the first to demonstrate the influence of the emotions on 

 the health of the body ? That a good circulation is associated 

 with cheerfulness is a familiar fact, and how this organic 

 jauntiness sometimes jars on the tired and sorrowful! But 

 there is the converse proposition that cheerfulness makes 

 for health. It was said of old time : " he that is of a merry 

 heart hath a continual feast ", and " a merry heart is the 

 life of the flesh ". Now, what the researches of Pavlov, 

 Cannon, Carlson, Crile, and others have done is to demon- 

 strate experimentally that pleasant emotions favour the 

 secretion of the digestive juices, the rhythmic movements 

 of the food-canal, and the absorption of the aliment Con- 

 trariwise, unpleasant emotional disturbance and worry of 

 all sorts have been proved to have a retardative influence 

 on the digestive processes. When the hungry man sees the 

 well-laid table his mouth waters, but every one knows that 

 a memory or an anticipation will also serve to move at 

 least the first link in the digestive chain. " It is now well 

 known," says Professor Dearborn, " that no sense-experi- 

 ence is too remote from the innervations of digestion to be 

 taken into its associations, and serve as a stimulus of diges- 

 tive movements and secretions." Emotion may influence 

 the production of adrenalin by the core of the adrenal glands, 

 and a slight increase in this potent 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. From the non-mechanistic position which 

 we have defended in these lectures, it is of great interest 

 and importance that 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 



