AMMONIA AND NITRIC ACID. 37 



however, on account of the strong tendency which it 

 has to unite with other bodies, such as carbonic acid, 

 sulphuric acid, etc. When it can not find any thing 

 else, it is at once absorbed by water, which will take 

 up an immense quantity of it before becoming satu 

 rated. A pint of cold water will absorb between 6 

 and 700 pints of ammonia. The aqua ammonia of 

 the shops, is water through which ammonia has been 

 passed until it is very strong. By smelling of it, the 

 extremely pungent and peculiar odor of ammonia is 

 perceived. The strong aqua ammonia is so powerful 

 in its effects as to take away the breath, and cause a 

 momentary suffocation. A more agreeable form of 

 ammoniacal odor is in the ordinary smelling salts. 

 These are usually nothing more than carbonate of am 

 monia, scented in various ways with other perfumes. 



The properties of ammonia ought to be understood 

 by every farmer, because it is a substance of much 

 importance : it does not exist so abundantly in the 

 soil as do many or most other necessary ingredients, 

 and consequently he ought to know how best to in 

 crease its amount, and how to keep it on his farm 

 when he has got it there. 



Ammonia is very easily lost, because driven from 

 its combinations with great facility. If, for instance, 

 you mix with muriate of ammonia, a compound which 

 has little or no smell of the gas, some quicklime, and 

 rub the two together, there will immediately a strong 

 smell of ammonia be perceived, passing off into the air 

 and disappearing. This is a reason why quicklime 

 should not be mixed with manures containing am 

 monia, as that gas is driven off by it, and the value 

 of the manure greatly diminished. 



Nitric acid (common aquafortis) is another impor- 



tant source of nitrogen. This acid is composed of 



nitrogen and oxygen. It is to be found in druggists' 



shops, and is a nearly colorless liquid, having a pe- 



4 



