Chap. II.
COMPOSITION AND USE OP MINERALS.
645
lime water, nor does water absorb it, except after it has been boiled for a considerable time.Nitrogen forms four-fifths, by bulk, of atmospheric air, and is found in coal, in the nitrates,and abounds in the materials of the animal kingdom. Its specific gravity, as compared withair, is 0 976. At a mean temperature and pressure, 100 cubic inches weigh 3016 grains.Its specific gravity, in reference to hydrogen, is 14 to 1.
Nitrous Oxide or Protoxide of Nitrogen, gaseous, colourless, with a sweet taste and slightodour, supports combustion brilliantly, and acts powerfully on the animal economy wheninhaled. When agitated with water it is absorbed, taking up an equal bulk, and whenheated it is evolved unchanged.
At a pressure of fifty atmospheres, this gas lias been obtained in a liquid form.
Nitrogen
1
-
14
-
63*3
-
1*0
-
30*16
Oxygen
- 1
-
8
-
36*7
-
0*5
-
17*05
1
22
100*0
1*0
47*21
13y passing it through a bright red heat in a porcelain tube, it is resolved into oxygen,nitrogen, and nitrous acid.
Nitric Oxide or Deutoxide of Nitrogen is a colourless, uncondensible gas , and cannot berespired. When mixed with air, it combines with the oxygen, producing red fumes ofnitrous acid. Its specific gravity, compared with hydrogen, is 15 to 1. ICO cubic inchesweigh 32*137 grains, and compared with air, its specific gravity is as 1*038 to 1000. Itis permanent over water. It is fatal to animals when breathed.
Nitrogen
1
14
46*67
,
Oxygen
2
16
-
53*33 -
1
1
30
100*00
2
Ifutwnitrous Acid forms distinct salts by
combining with
the salifiable bases.
liquid, green and very
volatile.
Nitrogen
1
14
-
36*8
10
Oxygen
3
24
-
63*2
1*5
4
38
100 0
Nitrous Acid is used as an oxidating agent, particularly when mixed with nitric acid.Its specific gravity, as compared with hydrogen, is as 46 to 1 ; to air 3*19 to 1, and 100 cubicinches weigh 98*8 grains. When liquid it is of an orange colour, specific gravity 1*452,and boils at 82°, and a red heat decomposes it.
When nitrous acid is poured into water, it is quickly decomposed, nitric oxide is dis-
engaged, and the fluid
assumes a greenish colour.
Nitrogen
1
14
30*4
1
Oxygen
4
32
69*6
2
1
46
100-0
1
Nitrous acid does not unite with bases, but forms with them hyponitrites and nitrates.
Nitric Acid is transparent and colourless when pure, and is decomposed when passed invapour through a red-hot tube. Its specific gravity varies between 1 *4 and 1*5, and it
always contains water.
Nitrogen - 1
14
25-9
Oxygen - 5
-
40
-
74*1
1
54
100*0
The salts called Nitrates are compounds of the anhydrous acid and a salifiable base;they are soluble in water, and crystallisable. The liquid nitric acid in its utmost state ofconcentration consists of
Anhydrous nitric acid
1
54
-
75
Water
2
18
-
25
1
72
100