PROPERTIES OF MATTER 17 



Some substances do not crystallize; these are called 

 amorphous substances. Crystalline bodies may be rec- 

 ognized by their form, or sometimes by the shining sur- 

 faces that they show when in a mass together. Butter, 

 glass, wood, flour, paper, coal, cloth, and wax are exam- 

 ples of amorphous substances. 



25. Capillarity. The adhesive force with which 

 some liquids are attracted to certain solid substances 

 causes a useful and interesting action called capillary 

 action or capillarity. 



Experiment 19. Put water into a clean glass tumbler and 

 carefully note the surface of the water where it meets the 



Now put a clean glass tube of very small bore down into the 

 water vertically. (An old thermometer tube, open at both ends, 

 may be used.) Note the height of water in the tube. What force 

 holds it in that position? 



Water has so great an adhesion for glass .that small 

 amounts of it may be raised by means of this force. 

 The smaller the tube, the higher that small amount of 

 water will rise in it. The oil rises through a lamp wick 

 by capillarity, the wick being a woven mass of tiny 

 fibers. 



26. Inertia. One property of matter which, though 

 very passive, is of great importance is that of inertia. 

 To state it briefly, inertia means the complete lack of 

 any ability of matter to cause or to change motion. No 

 body at rest can start itself moving ; some force must 

 be used, and then the body is started gradually. Also 

 no moving body can stop itself or in any way change 



