CHEMISTRY. 51 



AMMONIA ITS PROPERTIES AND RELATIONS. 



Ammonia is a colorless gas, having a strong, pungent odor 

 and alkaline taste: it is composed of one proportion of nitro- 

 gen and three of hydrogen: its equivalent number then is 17. 

 It is slightly combustible, but does not support combustion. 

 " Ammunia is rapidly absorbed by water, which takes up 780 

 times its volume at 32:" this is called water of ammonia, or 

 spirits of hartshorn, it has a specific gravity about one-tenth 

 less than water, and boils at 120. In its power of neutrali- 

 zing acids, it ranks next to lime, being a powerful base: it 

 forms, with the metallic salts and with acids, many compounds. 

 Ammoniacal gas does not support respiration, animals are 

 speedily suffocated by it, and living plants confined in it soon 

 wither and die. It is absorbed largely by porous bodies, such 

 as charcoal, burnt brick, burnt clay, &c., charcoal is said to 

 absorb 95 times its own bulk. 



Ammonia is sufficiently caustic to destroy both animal and 

 vegetable substances. It is remarkable that the two gases 

 which form ammonia, having neither taste nor odor when 

 separate, produce, when united in certain proportions, a gas so 

 intensely strong, pungent, and acrid. Ammonia being only 

 about three-fifths the weight of common air, it rises and 

 mingles with the air when it is set free, unless it is retained 

 by some substance with which it will unite and form a solid 

 substance not volatile. The salts of ammonia are easily soluble 

 in water. 



Ammonia exists in considerable abundance in nature, it is 

 almost universally diffused, but does not enter as a constituent 

 into any of the mineral masses of the earth's crust. It is found 

 mostly in a state of combination with acids, in the form of 

 nitrate, muriate and carbonate of ammonia. It is evolved 

 largely by the decay of animal and vegetable matters, and 

 does not remain long in a free state in the air, but combines 



