52 BURNING OR OXIDATION 



friction produced raises the temperature of the phosphorus to 

 a point where it can combine with oxygen. The burning phos- 

 phorus kindles the wood of the match, and from the burning 

 match the fire is kindled. But matches have been in use less 

 than a hundred years! Primitive man kindled his camp fire 

 by rubbing pieces of dry wood together until they took fire, and 

 this method is said to be used among some isolated distant tribes 

 at the present time. If you want to convince yourself that fric- 

 tion produces heat, rub a cent vigorously against your coat and 

 notice how warm the cent becomes. A later and easier way was 

 to stnke flint and steel together and to catch the spark thus pro- 

 duced on tinder or dry fungus. The burning tinder was then 

 put into a closed vessel, where it smoldered quietly until it was 

 needed for starting a fresh fire. Within the memory of some 

 persons now living, the tinder box was a valuable asset to the 

 home, particularly in the pioneer regions of the West. If any 

 accident happened to the tinder box, there was great consterna- 

 tion in the household, because in order to start a new fire, the 

 primitive method had to be resorted to, or a long journey had to 

 be made to the nearest neighbor for the loan of a tinder box. 



Safety matches. Ordinary phosphorus, while excellent as a 

 fire-producing material, is dangerously poisonous, and those to 

 whom the dipping of wooden strips into phosphorus is a daily 

 occupation suffer from a terrible disease which usually attacks 

 the teeth and bones of the jaw. The teeth rot and fall out, 

 abscesses form, and bones and flesh begin to decay. The only 

 way to prevent the spread of the disease is to remove the affected 

 bone, and in some instances it has been necessary to remove the 

 entire jaw. Then, too, matches made of yellow or white phos- 

 phorus ignite easily, and, when rubbed against any rough surface 

 are apt to take fire. Many destructive fires have been started 

 by the accidental friction of such matches against rough surfaces. 



For these reasons the introduction of the so-called safety 



