STALE BEER. 275 



Q. Why is BEER made STALE, by being 

 exposed to the AIR? 



A. Because air absorbs its carbonic 

 acid, which gave it "life." 



Q. Wliy is PORTER made STALE, by being 

 exposed to the AIR ? 



A. Because air absorbs its carbonic 

 acid, which gave it "life." 



Q. Why does the EFFERVESCENCE of soda 

 water and ginger beer so soon go off? 



A. Because air absorbs the carbonic 

 acid, which produced the effervescence. 



Q. Why is BOILED WATER FLAT and insipid ? 



A. Because the whole of the carbonic 

 acid is expelled by boiling, and absorbed 

 by the air. 



Q. Why does WATER become FLAT and insipid, 

 after it has been DRAWN some time ? 



A. Because air absorbs its carbonic 

 acid; and when its carbonic acid is 

 absorbed, the water is flat and insipid. 



Q. Why should spring WATER (used for 

 WASHING) be exposed to the AIR ? 



A. Spring water contains carbonic 

 acid ; but (by being exposed to the air) 

 this carbonic acid is absorbed, and the 

 water becomes more soft. 



