a sea-port town of Cornwall in England, situated on the river Tamar, having sufficient depth of water for large ships. Saltash is a borough town, sends two members to parliament, and contained 1478 inhabitants in 1811. It is distant 5 miles N.W. from Plymouth, 220 miles W.S.W. from London, and is in W. Long. 4. 6. N. Lat. 50. 24.
SALTOATS, a sea-port town of Ayrshire in Scotland, and on the frith of Clyde, at the end of the 17th century consisted of only four houses, but contained 1684 inhabitants in 1811. It is now a great resort of strangers in summer as a watering-place, has a considerable trade in coal and salt, with a rope-yard, the manufacture of sail-cloth and ship-building. It is 30 miles from Glasgow, and 18 from Ayr, and in W. Long. 4. 37. N. Lat. 55. 41.
SALTS, effects of, in producing great degrees of cold. In the account of the remarkable effects of refrigeric 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. TABLES, exhibiting a collective View of all the Frigorific Mixtures contained in Mr Walker's Publication, 1808.
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.
| Frigorific Mixtures, without Ice. | |----------------------------------| | 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 proportionally 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. TABLE II.—This Table consists of Frigorific Mixtures, composed of ice, with chemical salts and acids.
Frigorific Mixtures, with ice.
| Mixtures | Thermometer sinks | Deg. of cold produced | |----------|------------------|----------------------| | Snow, or pounded ice 2 parts Muriate of soda 1 | to $-50^\circ$ | * | | Snow, or pounded ice 5 parts Muriate of soda 2 Muriate of ammonia 1 | to $-12^\circ$ | * | | Snow, or pounded ice 24 parts Muriate of soda 10 Muriate of ammonia 5 Nitrate of potash 5 | to $-18^\circ$ | * | | Snow, or pounded ice 12 parts Muriate of soda 5 Nitrate of ammonia 5 | to $-25^\circ$ | * | | Snow 3 parts Diluted sulphuric acid 2 | From $+32^\circ$ to $-23^\circ$ | 55 | | Snow 8 parts Muriatic acid 5 | From $+32^\circ$ to $-27^\circ$ | 59 | | Snow 7 parts Diluted nitric acid 4 | From $+32^\circ$ to $-30^\circ$ | 62 | | Snow 4 parts Muriate of lime 5 | From $+32^\circ$ to $-40^\circ$ | 72 | | Snow 2 parts Chryst. muriate of lime 3 | From $+32^\circ$ to $-50^\circ$ | 82 | | Snow 3 parts Potash 4 | From $+32^\circ$ to $-51^\circ$ | 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.
| Combinations of Frigorific Mixtures. | |-------------------------------------| | Mixtures. | Thermometer sinks. | Deg. of cold produced. | | Phosphate of soda 5 parts | From 0° to −24° | 34 | | Nitrate of ammonia 3 | | | | Diluted nitric acid 4 | | | | Phosphate of soda 3 parts | From −34° to −50° | 16 | | Nitrate of ammonia 2 | | | | Diluted mixed acids 4 | | | | Snow 3 parts | From 0° to −46° | 46 | | Diluted nitric acid 2 | | | | Snow 8 parts | From −10° to −56° | 46 | | Diluted sulphuric acid 3 | | | | Diluted nitric acid 3 | | | | Snow 1 part | From −20° to −60° | 40 | | Diluted sulphuric acid 1 | | | | Snow 3 parts | From +20° to −48° | 68 | | Muriate of lime 4 | | | | Snow 3 parts | From +10° to −54° | 64 | | Muriate of lime 4 | | | | Snow 2 parts | From −15° to −68° | 53 | | Muriate of lime 3 | | | | Snow 1 part | From 0° to −66° | 66 | | Chryst. muriate of lime 2 | | | | Snow 1 part | From −40° to −73° | 33 | | Chryst. muriate of lime 3 parts | | | | Snow 8 parts | From −68° to −91° | 23 | | Diluted sulphuric 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.
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.
Salt-Mines. See Salt.
Rock-Salt. See Salt.
Salt-Water, or Sea-water, Distillation of. See Sea-Water.
Neutral-Salts. See Chemistry, passim.
Salt Springs. Of these there are great numbers in different parts of the world, which undoubtedly have their origin from some of the large collections of fossil salt mentioned under the article Common Salt. See that article, and likewise Spring.