72 now . rtrtps PKt:r>. 



nu'lts, and gTi.lir.ni.v decoiniiosc.s into wiitcr and nitrous oxide, Ji 

 "langliiiiij s^is," as represented by the equation : — 

 NH4 NO3 = 3 HoO + N,0 



Xitric acid and the nitrates act as powerful oxidizing 

 agents, i. e., tkey readily yield nj) a portion or all their 

 oxygen to substances having strong affinities for tliis ele- 

 ment. If, for example, charcoal he warmed with strong 

 nitric acid, it is rapidly acted upon and converted into 

 carbonic acid. If thrown into melted nitrate of soda oi 

 saltpeter, it takes fire, and is violently burned to carbonid 

 acid. Similarly, sulphur, phosphorus, and most of tlio 

 metals, may be oxidized by this acid. 



When nitric acid oxidizes other substances, it itself loses 

 oxygen and suffers reduction to compounds of nitrogen, 

 containing less oxygen. Some of these compounds require 

 notice. 



Nitric Oxide, NO. — ^When nitric acid somewhat diluted 

 with water acts upon metallic copper, a gas is evolved, 

 which, after washing Avith water, is colorless and permanent. 

 It is nitric oxide. By exposure to air it tmites with oxy- 

 gen, and forms red, suff.icating fumes of nitric peroxide, 

 or, if the oxygen be not in excess, nitrous acid is formed. 



]Vitric Peroxide, (hyponitric acid,) N0„, appears as a 

 dark yellowish-red gas when strong nitric acid is ])Oured 

 npon copper or tin exposed to the air. It is procured in 

 a state of purity by strongly heating nitrate of lead : by 

 a cold apjiroaching zero of Fahrenheit's thei'mometer, it 

 may be condensed to a yelloAV liquid or even solid. 



Nitrous Acid, (anhydrous,) ^„0^, is produced when 

 nitric peroxide is mixed with water at a low temperature, 

 nitric acid being formed at the same time. 



mtric peroxide. Water. Nitric acid. ^'^T'i ''"''^' 

 -' anhydrous. 



4 NO, + H^ = 2 NHO3 + N, O, 



It may be procured as a blue liquid, which boils at the 

 freezing point of water. 



