2. The same thing is to be observed with regard to the respiration, which becomes more active; in consequence, the temperature of the body rises, and the nutritive exchanges, becoming more rapid, result in a rich alimentation of the organs and tissues. “In joy, all parts of the body receive advantage, and are likely to last longer; the cheerful and contented man is well nourished and remains young. It is a truism that people in good health are contented” (Lange). Joy also tends to make the secretions (lacteal, spermatic, etc.) more abundant. 3. The innervation of the voluntary muscles expresses itself by exuberance of movements, by joyful exclamations, laughter, and singing. Certain cases of extreme and sudden joy have been known to produce all the effects of alcoholic intoxication. Sir H. Davy danced in his laboratory after making the discovery of potassium. At the London International Congress of Psychology (1892), Münsterberg communicated the following experiments under the title of “The Psychological Foundation of the Feelings.” A line ten centimetres in length is drawn with the right hand. When this movement has been thoroughly practised, it should be repeated with closed eyes, passing the hand first from right to left, with a movement of centripetal flexion, then from left to right, with a movement of centrifugal extension. In such a case mistakes will be made, sometimes in the one direction, sometimes in the other. Let us repeat the same experiments under the influence of certain affective states (sadness, gaiety, anger, etc.), noting all errors and their direction. Münsterberg has discovered them to be determined by a very exact law. In vexation, the extensor movements (centrifugal) are too short (average error, 10 mm.), and the flexor movements (centripetal) too long, the average excess being 12 mm. In joy, on the other hand, the centrifugal movements are in excess by (on an average) 10 mm., and the centripetal movements too short by an average of 20 mm. From this he concludes that, in pleasure, motion tends to increase; in pain, to diminish. The manifestations of joy may be summed up in a single word—dynamogeny. Joy produces energy.