AND ABSORPTION 29 



copious flow. Dextrin and commercial peptone 

 caused a smaller flow. It has since been shown by 

 Edkins that these bodies, by their contact with 

 the mucous membrane of the pyloric end of the 

 stomach, induce the formation of a chemical messen- 

 ger, soluble in the plasma of the blood or lymph, 

 which has the property of exciting the activity of the 

 secretory glands of the cardiac end. To this substance 

 the name of " gastrin," or " gastric secretion," has 

 been given. 



In considering the interpretation of these researches 

 we find that, as usual, the scientist has but furnished 

 a belated explanation of the empirical experience of 

 the ages. If food is served in an uninviting manner 

 or for any other reason is eaten without appetite, 

 the proper reflex to excite the secretion of gastric 

 juice will be lacking, and dyspepsia may follow. Yet 

 the stimulus of appetite is not the only means of 

 exciting a flow. The man who rises from a generous 

 dinner has no appetite left, but gastric juice will 

 be needed in his stomach for two or three hours to 

 come, in order to deal with the food present. Nature 

 has adopted the beautiful device that when the first 

 gush of juice produced by the relish with which the 

 food was taken has ceased to flow, the soluble ex- 

 tractives which always accompany a flesh diet shall 

 be used to call forth a further supply. As long as 

 any of these bodies are to be found in the stomach, 

 so long will sufficient gastric juice be forthcoming. 

 When the stomach is empty, the flow ceases. We 

 see here the rational explanation of the ordering of 

 the courses of a dinner. First comes the soup, rich 



