SALTS, effects of, in producing great degrees of cold. In the account of the remarkable effects of frigorific mixtures, in which saline bodies act so important a part, given in our article CHEMISTRY, some errors had crept in. These errors, through the liberal attention of Mr Walker of Oxford, whose researches on this subject have been carried farther than any other chemist, we are enabled to correct, by laying before our readers the following tables, most obligingly communicated to us by that gentleman.
TABLE I.—This Table consists of Frigorific Mixtures, having the power of generating or creating cold, without the aid of ice, sufficient for all useful and philosophical purposes, in any part of the world, at any season.
| Mixtures. | Thermometer sinks. | Deg. of cold produced. | |
|---|---|---|---|
| Muriate of ammonia | 5 parts | From +50° to +10°. | 40 |
| Nitrate of potash | 5 | ||
| Water | 16 | ||
| Muriate of ammonia | 5 parts | From +50° to +4°. | 46 |
| Nitrate of potash | 5 | ||
| Sulphate of soda | 8 | ||
| Water | 16 | ||
| Nitrate of ammonia | 1 part | From +50° to +4°. | 46 |
| Water | 1 | ||
| Nitrate of ammonia | 1 part | From +50° to -7°. | 57 |
| Carbonate of soda | 1 | ||
| Water | 1 | ||
| Sulphate of soda | 3 parts | From +50° to -3°. | 53 |
| Diluted nitric acid | 2 | ||
| Sulphate of soda | 6 parts | From +50° to -10°. | 60 |
| Muriate of ammonia | 4 | ||
| Nitrate of potash | 2 | ||
| Diluted nitric acid | 4 | ||
| Sulphate of soda | 6 parts | From +50° to -14°. | 64 |
| Nitrate of ammonia | 5 | ||
| Diluted nitric acid | 4 | ||
| Phosphate of soda | 9 parts | From +50° to -12°. | 62 |
| Diluted nitric acid | 4 | ||
| Phosphate of soda | 9 parts | From +50° to -21°. | 71 |
| Nitrate of ammonia | 6 | ||
| Diluted nitric acid | 4 | ||
| Sulphate of soda | 8 parts | From +50° to 0°. | 50 |
| Muriatic acid | 5 | ||
| Sulphate of soda | 5 parts | From +50° to +3°. | 47 |
| Diluted sulphuric acid | 4 | ||
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.
| Mixtures. | Thermometer sinks. | Deg. of cold produced. |
|---|---|---|
| Snow, or pounded ice 2 parts Muriate of soda 1 |
From any Temperature to |
* |
| Snow, or pounded ice 5 parts Muriate of soda 2 Muriate of ammonia 1 |
* | |
| Snow, or pounded ice 24 parts Muriate of soda 10 Muriate of ammonia 5 Nitrate of potash 5 |
* | |
| Snow, or pounded ice 12 parts Muriate of soda 5 Nitrate of ammonia 5 |
* | |
| Snow - - 3 parts Diluted sulphuric acid 2 |
From to | 55 |
| Snow - - 8 parts Muriatic acid 5 |
From to | 59 |
| Snow - - 7 parts Diluted nitric acid 4 |
From to | 62 |
| Snow - - 4 parts Muriate of lime 5 |
From to | 72 |
| Snow - - 2 parts Chryst. muriate of lime 3 |
From to | 82 |
| Snow - - 3 parts Potash 4 |
From to | 83 |
N. B. The reason for the omissions in the last column of this table, is, the thermometer sinking in these mixtures to the degree mentioned in the preceding column, and never lower, whatever may be the temperature of the materials at mixing.
TABLE III.—This Table consists of Frigorific Mixtures selected from the foregoing tables, and combined, so as to increase or extend cold to the extremest degrees.
| Mixtures. | Thermometer sinks. | Deg. of cold produced. | |
|---|---|---|---|
| Phosphate of soda 5 parts Nitrate of ammonia 3 Diluted nitric acid 4 |
From 0° to -34° | 34 | |
| Phosphate of soda 3 parts Nitrate of ammonia 2 Diluted mixed acids 4 |
From -34° to -50° | 16 | |
| Snow 3 parts Diluted nitric acid 2 |
From 0° to -46° | 46 | |
| Snow 8 parts Diluted sulphuric acid 3 Diluted nitric acid 3 |
From -10° to -56° | 46 | |
| Snow 1 part Diluted sulphuric acid 1 |
From -20° to -60° | 40 | |
| Snow 3 parts Muriate of lime 4 |
From +20° to -48° | 68 | |
| Snow 3 parts Muriate of lime 4 |
From +10° to -54° | 64 | |
| Snow 2 parts Muriate of lime 3 |
From -15° to -68° | 53 | |
| Snow 1 part Chryst. muriate of lime 2 |
From 0° to -66° | 66 | |
| Snow 1 part Chryst. muriate of lime 3 parts |
From -40° to -73° | 33 | |
| Snow 8 parts Diluted sulphuric acid 10 |
From -68° to -91° | 23 |
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.
Triple Salts, a kind of salts formed by the union of three ingredients; the common neutrals being composed only of two, as for instance, common alum, which is composed of sulphuric acid, alumina, and potash.