Imágenes de página

tities of woody and vegetable bodies brought down in the course of ages by the river Orinoco, which, becoming arrested in particular places by the influence of currents and eddies, and subject to the agency of subterranean fire in this region of volcanic action, have undergone those transformations and chemical changes which produce petroleum, converted into pitch upon being forced up to the surface and exposed to the air. There are waters, however, unconnected with bitumen, from whose surfaces flames dart out, without the liquid being at all hot. These contain inflammable gases, disengaged from masses of iron, zinc, and tin, dissolved by sulphuric and muriatic acids. Such are the fountains of Poretta Nuova, and a brook near Bergerac, which may be kindled by a lighted straw. Similar springs have appeared near Wigan in Lancashire, and Brosely in Salop, by the banks of the Severn.

7. Mineralised. Water is seldom found in a pure state, that is, without colour, taste, or odour. It is generally met with possessing these properties; and even when its odour is not cognizable by man, the keener sense of the camel will scent it afar off in the desert. Rain water is impregnated with whatever foreign ingredients may exist in the atmosphere through which it descends; and spring water, besides betraying the ingredients usually found in the rains from which it proceeds, becomes charged with a variety of substances and gases in percolating through the superficial strata of the earth. When these are present in an extraordinary degree, so as to produce some sensible effect upon the animal economy, the springs so constituted are termed mineral, and are both cold and thermal. The mineral waters may be grouped generally into the four following classes, and occur at the places annexed to them: Saline Aperient Waters. In Germany, at Carlsbad, Marienbad, Egra, Kissengen, Wiesbaden, Baden-Baden, Seidlitz, and Pullna. In England, at Cheltenham, Leamington, Harrowgate, Northwich, Epsom, and Ashby-de-la-Zouch. In Scotland, at Dumblane and Pitcaithly.

[ocr errors]

Alkaline Waters.—In Germany, at Carlsbad, Marienbad, Kissengen, Pullna, Saidschutz,
Ems, Töplitz, and Wiesbaden. In England, at Harrowgate, Scarborough, Cheltenham,
Leamington, and Bath. In France, at Vichy and Mont d'Or.
Chalybeate and Acidulous Waters. In Germany, at Spa, Pyrmont, Schwalbach,
Marienbad, Aix-la-Chapelle, and Seltzer. In England, at Tonbridge, Harrowgate, and
Brighton. In Scotland, at Peterhead.

Sulphureous Waters. — In Germany, at Aix-la-Chapelle. In the Pyrenees, at Bareges.
In England, at Harrowgate, Askern, and Kedleston. In Scotland, at Moffat and
Strathpeffer. The foreign sulphureous springs mentioned are hot; the domestic,

The waters of many of the chalybeate springs frequently hold in solution so large a quantity of iron, as to encase with a ferruginous deposit the channels through which they pass, depriving of their natural green the mosses and grasses which are laved by the stream, and covering them with a yellow incrustation. The brine springs of Northwich, which rise up through beds of rock-salt, are also so fully saturated, as to yield an annual supply of upwards of forty thousand tons of salt manufactured from them, besides the large quantity taken from the mines. But of all mineral ingredients, lime combined with carbonic acid occurs in the greatest abundance in springs, some of which are thermal. The deposition of the calcareous matter held in solution takes place when the acid is dissipated in the atmosphere, and extensive formations are produced. So rapid is the precipitation of carbonate of lime at the hot baths of St. Vignone, in Tuscany, that half a foot of solid travertine is the annual product near their source. The hot waters of Hierapolis have been similarly productive. This city, now a site of desolate ruins, was formerly one of the most flourishing in Asia Minor, and was resorted to for its thermal

[graphic][subsumed][merged small][subsumed]

springs, celebrated in a still extant inscription:- "Hail golden city Hierapolis! the spot to be preferred before any in wide Asia, revered for the rills of the nymphs, adorned with splendour!" The ancients speak of the transforming power of the waters, and relate that being conducted about the vineyards and gardens, the channels became long fences, each a single stone. There is now a powerful hot spring feeding numerous rills, and a calcareous cliff, an entire deposition from it. The occurrence of petrifactions, which puzzled science a century ago, and which rustic ignorance accepted as instances of the real transmutation of different objects into stones, is now well known to arise from the deposition upon them of the earthy ingredients of the waters to which they are exposed, investing them with a calcareous or siliceous crust. The Dripping Well at Knaresborough, on the

banks of the Nidd, often visited on account of its inviting scenery, and the cave of Eugene Aram in the neighbourhood, is a curious petrifying spring; and at the Matlock Wells the process of petrification is shown, objects which are put into them becoming soon encrusted with the limestone precipitated from the water as it evaporates. A considerable number of springs have recently been found to contain iodine or bromine. Those which issue from the lias at Leamington, Gloucester, Tewkesbury, and Cheltenham, contain iodine. The saline aperient waters of Epsom contain a small quantity of bromine, which is also found in the springs from the coal formation of Ashby-de-la-Zouch, Newcastle, and Kingswood. In several European springs, a remarkable animal substance


Dripping Well, Knaresborough.

has been detected, termed glairine, which may be derived from strata containing animal fossil remains, through which the water percolates.

Such are the chief peculiarities of the subject of this chapter. No apology need be offered for devoting so much space to it; for, however incompetent to explain all the phenomena, there can be no difference of opinion as to the high interest and practical utility of the phenomena themselves. The springs are the sources of the rivers which fertilise the soil through which they flow, and form the navigable channels which offer nations a convenient medium of intercommunication. To the geologist, they speak in the language of comment respecting the interior constitution of the globe, by their occasional high temperature and mineral composition, and the mode in which many of its strata have been produced, by the solid products in course of formation from their waters. The medicinal virtue of their streams is also a beneficial item of no mean importance; and whether welling through the loose sand and stony pavement of the Arabian desert, or breaking

forth at the grassy foot of a grove-crowned hill, the fountains of the earth are inviting objects of contemplation, through their association with the ideas of purity and benevolence, independently of being beautiful parts of natural scenery. Hence we may sympathise with the sentiment that inspired the ancient song of the Well, and regard as an appropriate homage, when under due restraints, that principle of veneration for the waters which pervaded the mind of all antiquity, and has survived in some rural customs to the present day. Milton, in his Comus, alludes to the honours formerly paid to the Severn:

"The shepherds at their festivals

Carol her good deeds loud in rustic lays,

And throw sweet garland wreaths into her stream,

Of pansies, pinks, and gaudy daffodils."

There is an elegant custom still observed by the villagers of Tissington, in Derbyshire, of a similar kind-that of dressing their wells with flowers on Ascension day. There are five copious springs issuing out of the limestone, which are decorated with boughs of laurel and white thorn, interspersed with the flowers of the season, arranged in various patterns and inscriptions. The effect is singularly beautiful; and the procession of the peasantry to sing at each well-a graceful usage handed down from a remote age -forms a very agreeable spectacle.



[graphic][merged small]

IVERS constitute an important part of the
aqueous portion of the globe. With their
tributaries, the small streams and rivulets, they
form a numerous family, of which lakes,
springs, or the meltings of ice and snow,
upon the summits of high mountain chains,
are the parents. The Shannon has its source
in a lake; the Rhone in a glacier; and the
Abyssinian branch of the Nile in a confluence
of fountains. The country where some of
the mightiest rivers of the globe have their
rise, has not yet been sufficiently explored to
render their true source ascertainable.
origin of others is doubtful, owing to a num-
ber of rills presenting equal claims to be con-


sidered as the river-head; but many are clearly referable to a single spring, the current of which is speedily swelled by tributary waters, ultimately flowing in broad and deep channels to the sea. Inglis, who wandered on foot through many lands, had a fancy, which he generally indulged, to visit the sources of rivers, when the chances of his journeys threw him in their vicinity. Such a pilgrimage will often repay the traveller by the scenes of picturesque and secluded beauty into which it leads him; and even when the primal fount is insignificant in itself, and the surrounding landscape exhibits the tamest features, there is a reward in the associations that are instantly wakened up

« AnteriorContinuar »