The following Tables were drawn up by Mr. Walker from actual experiments. They show the degree of cold, or the reduction of temperature, which may be obtained by the different combinations mentioned in the first column.

Table I. Frigorific Mixtures- Without Ice

Mixtures.

Thermometer sinks.

Degree of cold produced.

Parts.

Muriate of ammonia

5

Nitrate of potassa -

5

From + 50° to + 10°

40

Water - -

16

Muriate of ammonia

5

Nitrate of potassa -

5

From + 50° to + 4°

46

Sulphate of soda -

8

Water - -

16

Nitrate of ammonia

1

From + 50° to + 4°

46

Water - -

1

Nitrate of ammonia

1

Carbonate of soda -

1

From+ 50° to-7°

57

Water - -

1

Sulphate of soda -

3

From+ 50° to-30°

80

Diluted nitric acid -

2

Sulphate of soda -

6

Muriate of ammonia

4

From+ 50° to-10°

60

Nitrate of potassa -

2

Diluted nitric acid -

4

Sulphate of soda -

6

Nitrate of ammonia

5

From+ 50° to-14°

64

Diluted nitric acid -

4

Phosphate of soda -

9

From+ 50° to-12°

62

Diluted nitric acid -

4

Phosphate of soda -

9

Nitrate of ammonia

6

From+ 50° to-21°

71

Diluted nitric acid -

4

Sulphate of soda -

8

From+ 50° to -0°

50

Muriatic acid - -

5

Sulphate of soda -

From+ 50° to-3°

53

Diluted sulphuric acid

N. B. If the materials are mixed at a warmer temperature than that expressed in the table, the effect will be proportionably greater; thus, if the most powerful of these mixtures be made when the air is + 85°, it will sink the thermometer to + 2°.

Table II. Frigorific Mixtures- With Ice

Mixtures.

Thermometer sinks.

Degree of cold produced.

Parts.

From any temperature

Snow, or pounded ice

2

to-5°

*

Muriate of soda -

1

Snow, or pounded ice

5

Muriate of soda -

2

to-12°

*

Muriate of ammonia

1

Snow, or pounded ice

24

Muriate of soda -

10

to-18°

*

Muriate of ammonia

5

Nitrate of potassa -

5

Snow, or pounded ice

12

Muriate of soda -

5

to-25°

*

Nitrate of ammonia

5

Snow - - -

3

From+ 32° to-23°

55

Diluted sulphuric acid

12

Snow - - -

8

From +32° to-27°

59

Muriatic acid -

5

Snow - - -

7

From+ 32° to -30°

62

Diluted nitric acid

4

Snow - - -

4

From+32° to-40°

72

Muriate of lime -

5

Snow - - -

2

From+ 32° to-50°

82

Cryst. muriate of lime

53

Snow - - -

3

From+32°to-51°

83

Potassa - -

4

N. B. The reason for the omission in the last column of this table, is the thermometer sinking in the mixtures to the degree mentioned in the preceding column, and never lower, whatever may be the temperature of the materials at mixing.

Table III. Combination Of Frigorific Mixtures

Mixtures.

Thermometer sinks.

Degree of cold produced.

Parts.

Phosphate of soda -

5

Nitrate of ammonia

3

From 0° to- 34°

34

Diluted nitric acid

4

Phosphate of soda

3

Nitrate of ammonia

2

From-34° to -50°

16

Diluted mixed acids

4

Snow - - -

8

Diluted sulph. acid Or, Diluted nit. acid

3

From- 10° to-56°

46

3

Snow - - -

3

From 0° to-46°

46

Diluted nitric acid

2

Snow - - -

1

From-20° to-60°

40

Diluted sulphuric acid

2

Snow - - -

3

From+ 20° to-48°

68

Muriate of lime -

4

Snow - - -

3

From+10° to-54°

64

Muriate of lime -

4

Snow - - -

2

From + 15° to-68°

53

Muriate of lime -

3

Snow - - -

1

From 0° to- 66°

66

Cryst. muriate of lime

e2

Snow - - -

1

From-40° to - 739

33

Cryst. muriate of lime

3

Snow - - -

1

From -68° to-91°

23

Diluted sulph. acid

10

N. B. The materials in the first column are to be cooled, previously to mixing, to the temperature required, by mixtures taken from either of the preceding tables.