38 LABORATORY EXERCISES, 



5. Name several foods already studied which 



could be partially digested by saliva. 



6. Hold a small amount of the boiled dilute 



starch paste in the mouth. What is the 

 taste at first ? Do you notice any change; 

 if so, what change? 



B. By pancreatic juice. 



1. Dissolve a little pancreatin in water. Test 



a small portion of it with Fehling's solu- 

 tion. What is your conclusion? 



2. Add some pancreatin solution to some of the 



starch paste; warm and test with Feh- 

 ling's solution. Result? 



C. What digestive juices of the human body act 



upon starch? What change do they cause? 



20. DIGESTION OF MINERAL SUBSTANCES. 



Materials : Table-salt, phosphate of lime, diluted hydrochloric 

 acid; evaporating-dish, alcohol-lamp. 



A. Soluble salts. 



Put some table-salt into a test-tube, add 

 water, and shake well. 



1 . Does the salt dissolve ? How do you know? 



2. In what part of the alimentary canal may 



salt become liquefied, and how? 



3. What is meant by a soluble salt or soluble 



mineral substance? 



B. Insoluble salts. 



Put some phosphate of lime (one of the con- 



