246 PHYSIOLOGICAL CHEMISTRY 



18. Adsorption. The student is familiar with a demonstra- 

 tion of adsorption in the decolorization of solutions by means of 

 charcoal. 



Place a small amount of dry starch in a test tube and add 2-3 

 c.c. of a very dilute iodine solution (straw color). Shake well, 

 and allow the starch to settle. Observe the color of the super- 

 natant liquid. What has happened ? 



