188 METALLOIDS. 



460. DECOLORIZING EFFECTS OF CHAR- 



Describe its 



decolorizing COAL. Charcoal has, also, the effect of 

 power. removing coloring matters, and 



bitter and astringent flavors from liquids. 

 Thus, ale and porter lose both color and fla- 

 vor by being filtered through sugar. Sugar 

 refiners take advantage of this property, in 

 decolorizing their brown syrups. Animal 

 charcoal, or bone black, is best adapted to these uses. 

 As an illustration of the decolorizing effect of char- 

 coal, let water colored with a few drops of ink, be 

 filtered through bone black. The color will be found to 

 disappear, in the process. 



461. COMBUSTION OF CARBON. All of 

 of the <y**- tne forms of Carbon are combustible. The 

 bustionof combustion of charcoal, in air, is a famil- 



carbon ? 



iar fact. Its combustion in oxygen has 

 has been already shown. The diamond, and 

 plumbago, will also burn in a vial of oxygen 

 gas, if first intensely heated. The product of 

 their combustion, is precisely the same as that 

 of charcoal. From the carbonic acid, which 

 is produced in the combustion, the carbon 

 may be obtained in the form of lamp black. The 

 nature of the diamond is thus conclusively established. 



462. REDUCTION OF ORES BY CHARCOAL. 



How does 



charcoal re- The affinity of carbon for oxygen, at a 

 duce metals? hi g h temperature, is very intense. It de- 

 prives most ores of their oxygen, and converts them 

 into metals. An agent which thus produces metals 

 from their compounds, is called a reducing agent, and 



