CARBOK 61 



Charcoal. If a piece of charcoal is examined care- 

 fully it will be seen to look very much like a small 

 block of wood. And such, in fact, it is. It is usually 

 made by heaping up the small blocks of wood into 

 mounds and covering the whole with soil and turf to 

 exclude the air. Then a fire is started underneath the 

 wood and although some of the wood burns, yet the 

 greater portion only smolders. The result is that all 

 other substances are driven off, leaving practically 

 pure carbon. A more modern method of producing 

 charcoal is to heat wood in closed iron ovens. The 

 principle involved in either case is the same; namely, 

 to break down the compounds which comprise wood 

 into simpler substances, and drive off all but carbon. 

 Animal carbon is prepared by burning bones away 

 from air. 



Uses of charcoal. Because of its porous nature, 

 charcoal is a great absorber of gases. This quality 

 renders it of great value in contributing to our com- 

 fort and welfare. The unpleasant odors which arise 

 from sewers can be prevented by suspending bags of 

 charcoal in the man-holes. Cistern water is kept sweet 

 and clean by filtering through charcoal. In many 

 homes in our cities all water used for drinking and 

 cooking purposes is passed through charcoal filters. 

 In passing through the porous charcoal the impurities 

 are removed. However, unless the filter is cleaned 

 frequently it may become a menace to health rather 

 than a benefit. The pores in the filter become clogged 



