72 CHEMICAL ACTION. 



Q. Why are SOME parts of the ceiling 

 BLACKER and more filthy than others ? 



A. As the air cannot penetrate the 

 thick joists of the ceiling, it passes by 

 those parts, and deposits its soot and 

 dust on those which are more penetrable. 



Q. What is CHARCOAL ? 



A. Wood which has been exposed 

 to a red heat, till it has been deprived of 

 all its gases and volatile parts. 



Q. Why is a CHARCOAL FIRE hotter than a 

 u'oodfire ? 



A. Because so large a quantity of 

 water has been abstracted from the fuel, 

 by the red heat to which it has been 

 already exposed. 



Q. Why does charcoal REMOVE the TAINT of 

 meat ? 



A. Because it absorbs all odoriferous 

 effluvia, whether they arise from putrefying 

 animal or vegetable matter. 



Q. Why is WATER PURIFIED by l>eing filtered 

 through charcoal? 



A. Charcoal absorbs the impurities 

 of the water, and removes all disagree- 

 able tastes and smells, whether they 

 arise from animal or vegetable matter. 



