22O 



ELEMENTS OF PHYSIOLOGY 



produced artificially by the action of vegetable diastase, 

 which resembles ptyalin or the ferment found in saliva. 

 Glucose, produced artificially by boiling starch with dilute 

 sulphuric acid is of the same chemical composition as 

 grape sugar, but the presence of sulphur and other chemi- 

 cals interferes with its usefulness as a food. 



Dextrin is intermediate between starch and sugar. 



Starch, unlike the sugars, is insoluble in cold water. 



392. Analysis of Digestion. 



393. THOUGHT LESSON. 



(Answers to be found by reference to table called 

 "Analysis of Digestion.") 



1. In which of the digestive organs is only one kind 

 of secretion furnished from glands ? 



2. In which organ are three kinds of secretions fur- 

 nished it by glands ? 



3. Which classes of foods go through the lymphatics ? 



