126 CHEMISTRY. 



nia, which distills over and condenses in the water used to 

 wash the coal gas. It can also be obtained by distilling 

 animal substances, especially bones. It received the name 

 hartshorn from having been formerly obtained by the dis- 

 tillation of the horns of harts and deer. The name ammo- 

 nia comes from sal ammoniac ; and this was so called be- 

 cause it was first manufactured near the temple of Jupiter 

 Ammon by the distillation of camels' manure. 



161. The Production of Ammonia Explained. If you intro- 

 duce into a vessel the two gases of which ammonia is com- 

 posed, you can not in any way make them unite to form 

 this substance. You may heat them to any degree, and 

 they will not unite chemically, but will only be mixed to- 

 gether. But if you let these gases be together at the mo- 

 ment that they are produced, they will unite and form am- 

 monia. We will give you an illustration. If you heat some 

 potassium hydrate and iron filings together in a flask, hy- 

 drogen will be produced ; and if you heat iron filings and 

 potassium nitrate in another flask, nitrogen will be produced 

 there. Now if you conduct these two gases from these 

 flasks by tubes into another vessel, you will have only a 

 mixture of them ; but if you put all the materials into one 

 flask, nitrogen is liberated from the potassium nitrate, and 

 hydrogen from the potassium hydrate just as before, and 

 the two gases, being in each other's company at the mo- 

 ment they are produced, unite and form ammonia. The 

 chemist, therefore, says that they must be in their nascent 

 state in order to unite, as explained in 42. Ammonia is 

 formed in the decomposition of animal and vegetable sub- 

 stances, because the two gases nitrogen and hydrogen are 

 evolved simultaneously, and are present in their nascent 

 state. 



162. Preparation of Ammonia. Ammonia is never actu- 

 ally prepared by heating the substances named above, 



