216 METALLOIDS. 



AMMONIA. 

 536. DESCRIPTION. Ammonia is a col- 



WTiat is am- 

 monia? orless gas, of pungent smell, and alkaline 



P r P erties -. It is exhaled from vdlcanoes, 

 and is a product of the decomposition of 

 all vegetable and animal matter. Its molecule contains 

 one atom of nitrogen to three of hydrogen. 

 mi . . .j 537. PRODUCTION FROM ITS ELEMENTS. 



What ^s said 



of its produc- Although nitrogen and hydrogen gases are 

 trogenandhy- the sole elements of ammonia, they cannot, 

 drogent under ordinary circumstances, be made to 



unite directly, and form it. Heat does not stimulate 

 their affinities sufficiently to bring about this result. 

 Electrical sparks passed, for a long time, through a 

 mixture of the gases, cause them to combine to a lim- 

 ited extent. 



538. PRODUCTION FROM NASCENT ELE- 



Production 



from its nas- MENTs. Iron, at a high temperature, ex- 

 cent elements. pelg hydrogen from or dinary hydrate of 



potassa, and nitrogen from nitre. If heated with both 

 together, it expels both nitrogen and hydrogen, and the 

 two nascent elements unite, to form ammonia. The 

 experiment may be performed by covering bits of potash 

 and nitre with iron filings, and heating them in a test- 

 tube. Another method of producing ammonia, through 

 the agency of platinum sponge, is described under the 

 head of Platinum. 



How is ammo- 539t PREPARATION. Ammonia is com- 

 ma common- monly made from salts that contain it, by 



ly prepared ? 



using some strong base to retain the acid, 



