ELEMENTS ATOMIC WEIGHTS MOLECULES, ETC. 11 



bustion, as in the case of the carbon filament of an electric 

 light bulb. 



11. Spontaneous Combustion. If the heat produced in 

 slow oxidation is not allowed to be dissipated, the tem- 

 perature of the combustible which is being oxidized may 

 gradually be raised till it attains its kindling temperature 



Blower to 

 Supply Air 



1 



FIG. 4. A down-draft forge. 



and it will then burst into flame. This is quite likely to 

 happen in the case of vegetable or animal oils with which 

 cloths may have been saturated. These oils are " drying 

 oils," that is, they are easily oxidized as shown by the 

 necks and stoppers of their containers, which are gummed 

 upon standing. This combustion is produced spontane- 

 ously, that is, by the internal development of heat without 



