[Foster's fine form. l. 113. Alluding to the beautiful statues of Lady Elizabeth Foster and of Lady Melbourn executed by the ingenious Mrs. Damer.]
115 V. GNOMES! you then taught transuding dews to pass
Through time-fall'n woods, and root-inwove morass
Age after age; and with filtration fine
Dispart, from earths and sulphurs, the saline.
[Root-inwove morass. l. 116. The great mass of matter which rests upon the lime-stone strata of the earth, or upon the granite where the lime- stone stratum has been removed by earthquakes or covered by lava, has had its origin from the recrements of vegetables and of air-breathing animals, as the lime-stone had its origin from sea animals. The whole habitable world was originally covered with woods, till mankind formed themselves into societies, and subdued them by fire and by steel. Hence woods in uncultivated countries have grown and fallen through many ages, whence morasses of immense extent; and from these as the more soluble parts were washed away first, were produced sea-salt, nitre, iron, and variety of acids, which combining with calcareous matter were productive of many fossil bodies, as flint, sea-sand, selenite, with the precious stones, and perhaps the diamond. See additional notes, No. XVII.]
1. "HENCE with diffusive SALT old Ocean steeps
120 His emerald shallows, and his sapphire deeps.
Oft in wide lakes, around their warmer brim
In hollow pyramids the crystals swim;
Or, fused by earth-born fires, in cubic blocks
Shoot their white forms, and harden into rocks.
[Hence with diffusive salt. l. 119. Salts of various kinds are produced from the recrements of animal and vegetable bodies, such as phosphoric, ammoniacal, marine salt, and others; these are washed from the earth by rains, and carried down our rivers into the sea; they seem all here to decompose each other except the marine salt, which has therefore from the beginning of the habitable world been perpetually accumulating.
There is a town in the immense salt-mines of Cracow in Poland, with a market-place, a river, a church, and a famous statue, (here supposed to be of Lot's wife) by the moist or dry appearance of which the subterranean inhabitants are said to know when the weather is fair above ground. The galleries in these mines are so numerous and so intricate, that workmen have frequently lost their way, their lights having been burnt out, and have perished before they could be found. Essais, &c. par M. Macquart. And though the arches of these different stories of galleries are boldly executed, yet they are not dangerous; as they are held together or supported by large masses of timber of a foot square; and these vast timbers remain perfectly sound for many centuries, while all other pillars whether of brick, cement, or salt soon dissolve or moulder away. Ibid. Could the timbers over water-mill wheels or cellars, be thus preserved by occasionally soaking them with brine? These immense masses of rock-salt seem to have been produced by the evaporation of sea-water in the early periods of the world by subterranean fires. Dr. Hutton's Theory of the Earth. See also Theorie des Sources Salees, par Mr. Struve. Histoire de Sciences de Lausanne. Tom. II. This idea of Dr. Hutton's is confirmed by a fact mentioned in M. Macquart's Essais sur Minerologie, who found a great quantity of fossil shells, principally bi-valves and madre-pores, in the salt-mines of Wialiczka near Cracow. During the evaporation of the lakes of salt-water, as in artificial salt-works, the salt begins to crystallize near the edges where the water is shallowest, forming hollow inverted pyramids; which, when they become of a certain size, subside by their gravity; if urged by a stronger fire the salt fuses or forms large cubes; whence the salt shaped in hollow pyramids, called flake-salt, is better tasted and preserves flesh better, than the basket or powder salt; because it is made by less heat and thence contains more of the marine acid. The sea- water about our island contains from about one twenty-eighth to one thirtieth part of sea-salt, and about one eightieth of magnesian salt. See Brownrigg on Salt. See note on Ocymum, Vol. II. of this work.]
125 "Thus, cavern'd round in CRACOW'S mighty mines,
With crystal walls a gorgeous city shines;
Scoop'd in the briny rock long streets extend
Their hoary course, and glittering domes ascend;
Down the bright steeps, emerging into day,
130 Impetuous fountains burst their headlong way,
O'er milk-white vales in ivory channels spread,
And wondering seek their subterraneous bed.
Form'd in pellucid salt with chissel nice,
The pale lamp glimmering through the sculptured ice,
135 With wild reverted eyes fair LOTTA stands,
And spreads to Heaven, in vain, her glassy hands;
Cold dews condense upon her pearly breast,
And the big tear rolls lucid down her vest.
Far gleaming o'er the town transparent fanes
140 Rear their white towers, and wave their golden vanes;
Long lines of lustres pour their trembling rays,
And the bright vault returns the mingled blaze.
2. "HENCE orient NITRE owes it's sparkling birth,
And with prismatic crystals gems the earth,
145 O'er tottering domes in filmy foliage crawls,
Or frosts with branching plumes the mouldering walls.
As woos Azotic Gas the virgin Air,
And veils in crimson clouds the yielding Fair,
Indignant Fire the treacherous courtship flies,
150 Waves his light wing, and mingles with the skies.
[Hence orient Nitre. l. 143. Nitre is found in Bengal naturally crystallized, and is swept by brooms from earths and stones, and thence called sweepings of nitre. It has lately been found in large quantities in a natural bason of calcareous earth at Molfetta in Italy, both in thin strata between the calcareous beds, and in efflorescences of various beautiful leafy and hairy forms. An account of this nitre-bed is given by Mr. Zimmerman and abridged in Rozier's Journal de Physique Fevrier. 1790. This acid appears to be produced in all situations where animal and vegetable matters are compleatly decomposed, and which are exposed to the action of the air as on the walls of stables, and slaughter-houses; the crystals are prisms furrowed by longitudinal groves.
Dr. Priestley discovered that nitrous air or gas which he obtained by dissolving metals in nitrous acid, would combine rapidly with vital air, and produce with it a true nitrous acid; forming red clouds during the combination; the two airs occupy only the space before occupied by one of them, and at the same time heat is given out from the new combination. This dimunition of the bulk of a mixture of nitrous gas and vital air, Dr. Priestley ingeniously used as a test of the purity of the latter; a discovery of the greatest importance in the analysis of airs.