450

Alkalies and Neutral Salts.

part III.

130°, the ammonia is again separated in the form of gas;and hence the necessity of keeping the receivers cold. Theproduct thus obtained is a saturated solution of ammonia;while muriate of lime remains in the retort, and may bedissolved out by twice its weight of water.

dualities. — Liquid ammonia is a limpid colourless fluid.It has a very strong pungent odour, an extremely acrid taste,and inflames the skin. Obtained according to the LondonCollege, its specific gravity is -9060, to the Edinburgh -9039,while that of the Dublin College is -9310. The following-table shows the strength of liquid ammonia of different de-grees of specific gravity within a certain range: (Temp. 50 aFah. Pressure 29-8 Barom.)

100 partsSp. Grav.

Contain of

100 partsSp. Grav.

Contain of

Ammonia.

Water.

Ammonia.

| Water.

-.9000

26-00

74-00

•9513

12-40

87-60

•9054

25-37

74-63

•9545

11-56

88-44

•9166

22-07

77-93

•9573

10-82

89-18

'9255

19-54

80-46

•9597

10-17

89-83

•9326

17-52

82-48

•9619

9-60

90-40

•9335

15-88

84-12 1

•9684

9-50

90-50

•94-35

14-53

85-47 1

•9639

9-09

90-91

•9476

13-46

86-54

•9713

7-17

92-83"

For ordinary purposes it is useful to know, that a phial capa-ble of containing 224 grains of distilled water can hold nomore than 216 grains of the strong solution.

Liquid ammonia assists the oxidizement of copper and•zinc; dissolves many of the metallic oxides; and unites withall the a"cids without effervescence, forming neutral salts. Itsaffinity for carbonic acid is so powerful, that it rapidly attractsit from the atmosphere; and hence the necessity of preservingit in well stopped small phials, as directed by the EdinburghCollege. The acids, the metallic salts, and alum are incom-patible in formulas .with it. The constituents of the ammoniait contains, according to the latest experiments of Mr. Davy,are 74 measures by bulk of hydrogen gas, and 26 of azotic gas;or, according to the analysis of Dr. Henry, 100 parts of am-monia consist of 80*36 of azote, and 19"64> hydrogen byweight. 1 The presence of carbonic acid in solution of ammo-nia may be readily detected by adding to it muriate of lime,which forms a precipitate if carbonic acid be present.

Medical properties and uses. ■ — This solution of ammonia is

« Davy's Researches, p. 68.

* Philosophical Transaclions t l809.