Page:A Treatise on Geology, volume 2.djvu/269

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CHAP. IX.
MODERN EFFECTS OF HEAT.
255



Warm Springs of the British Islands, Yielding Nitrogen, &c.

1. Bath.—The King's Bath spring rises through lias[1], at a temperature of 66° above that of the neighbourhood; contains saline ingredients, 15 grains in a pint (muriate of lime and magnesia); evolves 96.5 per cent, nitrogen, 3.5 oxygen, and some carbonic acid.
2. Bristol.—The Hot Well rises in carboniferous limestone, at a temperature of 25° above that of the place; contains saline ingredients, 6 grains in a pint (sulphate of soda and muriate of lime); evolves 92 per cent, nitrogen, and 8 oxygen.
3. Buxton, Derbyshire.—St. Anne's Well rises in carboniferous limestone, at a temperature of 33° above the vicinity; contains saline ingredients, only 1.8 grains in a pint (muriates of magnesia and soda); evolves nitrogen only.
4. Baltewell, Derbyshire.—The Bath spring rises in carboniferous limestone, at a temperature of 13° above the vicinity; contains saline ingredients, 3½ grains in a pint (sulphate of lime and muriate of soda); evolves nitrogen only.
5. Stony Middleton, Derbyshire.—The spring rises in carboniferous limestone, at a temperature of 14° above that of the vicinity; contains saline ingredients, 2 grains in a pint (sulphate of soda and magnesia, and muriate of lime); evolves nitrogen only.
6. Taafe's Well, near Cardiff.—Rises from coal strata, at a temperature of 21° above that of the vicinity; contains saline ingredients, only 1.2 grain in a pint (sulphate of magnesia); evolves 96i per cent, of nitrogen, and 3½ per cent, of oxygen.
?. Mallow, Co. Cork.—The Spa well rises in carboniferous limestone, at a temperature of 23° above that of the vicinity; contains saline ingredients, only 0.3 grain in a pint (carbonate of lime); evolves nitrogen 93½ per cent., and oxygen 65.

It is very surprising that the only hot springs of Great Britain should all rise through strata of the carboniferous system (mostly below the coal), or through others which rest unconformable upon them.

  1. Dr. Daubeny places the source of this spring in red sandstone, but we conjecture that it is likely the spring originates in the mountain limestone which lies unconformable below the lias and new red sandstone.