Q. Why are the ceilings of public offices so black and filthy?
A. The heated air ascending, carries the dust and fine soot to the ceiling; where the hot air escapes through the plaster, and leaves the soot and dust behind.
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 wood fire?
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?