266 AIR. 



bottom, he inhales the pernicious gas, 

 which kills him. 



Q. Why are the JUNGLES of Jarva and 

 Hindostan so FATAL to life ? 



A. Because vast quantities of carbonic 

 acid are thrown off by decaying vegetables; 

 and (as the wind cannot penetrate the 

 thick brushwood to blow it away) it 

 settles there, and destroys animal life. 



Q. Why are PERSONS sometimes KILLED by 

 having a CHARCOAL FIRE in their bed-rooms ? 



A. When charcoal is burned, the 

 carbon of the charcoal unites with the 

 oxygen of the air, and forms carbonic 

 acid gas, which is a narcotic poison. 



Q. Why does the carbonic acid gas of a 

 CHARCOAL FIRE RISE and DISPERSE itself about 

 the room; whereas the carbonic acid gas of a BEER 

 VAT SETTLES near the FLOOR ? 



A. The carbonic acid gas of a char- 

 coal fire is heated by the combustion of 

 the fuel, and rises ; but the carbonic acid 

 gas of a beer vat is not heated, and, 

 therefore, rests on the bottom, of the vat. 



Q. Why do persons throw LIME into BINS to 

 PREVENT their offensive SMELL, in summer time ? 

 A. Bins contain large quantities of 



