ATMOSPHERIC AIR AS THE FOOD OF PLANTS. 13 
When nitric peroxide is put in contact with solutions 
of an alkali, there results a mixture of nitrate and nitrite 
of the alkali. 
Nitric Hydrate of Nitrate of Nitrite of 
ain Water. 
peroxide. potash. potash. potash. 
eNO. +. 2KO:. =, NKO...+ NKO,.+ HO 
Nitrite of Ammonia, NH, NO, is known to the chem- 
ist as a white crystalline solid, very soluble in water. 
When its concentrated aqueous solution is gently heated, 
the salt is gradually resolved into water and nitrogen gas, 
This decomposition is represented by the following equa- 
tion : 
MET NOS 3) CRO oe 2 
This decomposition is, however, not complete. A por- 
tion of ammonia escapes in the vapors, and nitrous acid 
accumulates in the residual liquid. (Pettenkofer.) Addi- 
tion of a strong acid facilitates decomposition; an alkali 
retards it. When a dilute solution, 1 : 500, is boiled, but 
a small portion of the salt is décomposed, and a part of it 
is found in the distillate. Very dilute solutions, 1 : 100,00, 
may be boiled without suffering any alteration whatever. 
(Sché yen. ) 
Schénbein and others have (erroneously ?) supposed that 
nitrite of ammonia is generated by the direct union of 
nitrogen and water. Nitrite of ammonia may exist in the 
atmosphere in minute quantity. 
Nitrites ef potish and soda may be procured by strongly 
heating the corresponding nitrates, whereby oxygen gas is 
expelled. 
The Mutual Convertibility of Nitrates and Nitrites is 
illustrated by various statements already made. There 
are, in fact, numerous substances which reduce nitrates to 
nitrites. According to Schénbein, (Jow. Prakt. Ch., 84, 
207,) this reducing effect is exercised by the albuminoids, 
by starch, glucose, and milk-sugar, but not by cane-sugar. 
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