CAPILLARITY 107 



tubes which are as fine as a hair, or even finer. Let US 

 perform some experiments which show capillarity and 

 talk about it afterwards. 



Experiment 53. Examples of Capillarity. 



Apparatus: Several 6" pieces of glass tubing of 

 different diameters, two glasses, lamp wick, block of 

 wood. 



Materials: Cube .sugar, red ink, 



a. Fill one of the glasses with water and place the 

 tubes in it. Describe how the water goes up the tubes. 

 A little red ink, added to the water, will make it easier 

 to see the water in the tubes. In which tube does the 

 water go the highest? You can make a very fine glass 

 tube by heating a short piece of ordinary glass tubing in 

 the flame of a wing burner, and then suddenly pulling the 

 two ends as far apart as you can reach. Water will go 

 six or eight inches up such a tube. Try it. 



b. Fill one glass with water and place it upon the 

 block of wood. Now wet the lamp wick thoroughly, 

 wring it as dry as possible and 



bend it over the edge of the 

 glass so that it reaches the bot- 

 tom of the glass* while the 

 other end falls into the other 

 p"lass placed near the block. The 

 lower glass should be empty. 

 Tell what happens in a few min- 

 utes. What is this an example of? The oil in a lamp 

 reaches the flame in the same way. 



c. Dip one corner of a lump of sugar in some colored 



