112 LABORATORY MANUAL 



minutes at a temperature of 36 C. At the end of that 

 time what change do you observe in the milk? 



Exercise 75. Digestion in the Intestine. 

 Object: To determine the foods acted upon by the 

 pancreatic juice. 



Apparatus 



Corn starch Pancreatin 



Egg-white Bunsen burner 



Olive oil Test tubes and racks 



Hydrochloric acid (dilute) Test tube clamps 



Sodium hydroxide (dilute) 



Directions: In the small intestine the food is acted 

 upon by three digestive juices : intestinal, which is 

 secreted by the glands in the walls of the small 

 intestine; bile, secreted by the liver; pancreatic, 

 secreted by the pancreas. 



Prepare a weak solution of pancreatin by dissolving 

 a few grains of pancreatin in 50 c.c. of water. 



Prepare four test tubes as follows : 



In No. 1 place starch paste, 10 c.c. of pancreatin 

 solution, and a few drops of very dilute sodium 

 hydroxide. 



In No. 2 place starch paste, 10 c.c. pancreatin solu- 

 tion, and a few c.c. of hydrochloric acid. 



In No. 3 place a few bits of egg-white, pancreatin 

 solution, and sodium hydroxide. 



In No. 4 place 10 c.c. olive oil, pancreatin solution, 

 and sodium hydroxide. 



