42 LABORATORY EXERCISES 



the bottle, and note what happens. After the action has 

 become vigorous, prove that carbon dioxide is being formed. 

 After the action has ceased (it may be after several days), bring 

 the fermented solution to the instructor, so that he may distill 

 it, and may show that it contains alcohol. 



EXERCISE 41 

 LIME 



Apparatus and Materials. Small iron dish, test tube, bottle with 

 stopper, glass tube, lump of lime, sand, water. 



a. Put a lump of fresh lime, about the size of a walnut, into 

 your small iron dish, and add water, a few drops at a time, as 

 the lime absorbs it. Do not use an excess of water. If you 

 can see no sign of a reaction at first, try warming the dish 

 gently. Note how the " slaking" of lime takes place, and 

 describe the process. Watch the process of making mortar for 

 some building in your neighborhood, and see how lime is slaked 

 on a large scale. 



When your lime has ceased to react with water, mix it with 

 enough water to form a thick paste. Mix half of this paste 

 with clean sand, and lay it aside for a week or two. What 

 happens to it? 



Mix the remainder of the paste with more water, stir the 

 mixture (we call it "milk of lime"), and pour it into a bottle 

 which can be stoppered tightly. Let it stand until it settles, 

 or filter some of the milky solution. Prove that the clear 

 solution behaves like limewater. You can do this best by 

 putting some in a test tube, and blowing your breath slowly 

 through a tube reaching into the liquid. 



