"At the end of time The vapours rage (geysar), And playful flames Involve the skies." Ari Frode, the first historiographer of the north, who flourished in the eleventh century, was educated within a mile of the Geysers, yet makes no mention of them; nor are they referred to by a native Icelander, till the time of Svenson, bishop of Skalpolt, in the seventeenth century. But no argument can be founded upon this fact, to prove that the boiling fountains were not in full play when the first Norwegian colonists took possession of the soil, in the ninth century, more than that Herculaneum and Pompeii were not overwhelmed by the eruption of Vesuvius in the year 79, because Pliny, who saw the volcano explode, who lost his uncle by it, and minutely describes the event, omits all notice of the buried cities - one of the most unaccountable circumstances in the range of history. The explanation of these great efforts of nature, given by Sir C. Lyell, is simple and ingenious, founded upon the general supposition of a subterranean cavity where water. and steam collect, and where the free escape of the steam is prevented till it acquires sufficient force to discharge the water. He supposes water from the surface of the earth to penetrate into the cavity AD by the fissures FF; while at the same time steam, at an extremely high temperature, rises upwards through the fissures c c. When the steam reaches the cavity, a portion of it is at first con. densed into water; and it gradually raises the temperature of the water already there, till at last the lower part of the cavity is filled with boiling water, and the upper part with steam under high pressure. As the pressure of the steam increases, its expansive force becomes greater; and at length it forces the R boiling water up the fissure or pipe E B, and a considerable quantity runs over the rim of the basin. When the pressure on the steam in the upper part of the cavity is thus diminished, it expands till all the water, D, is driven to E, the bottom of the pipe; and when this happens, the steam rushes up with great velocity, as on the opening of the valve of a steam-boiler. Sir C. Lyell, upon the same principle, accounts for the eruption of volcanoes, referring it to the agency of steam upon melted lava accumulated in cavities in the bowels of the earth-a theory which, though not demonstrable, is invested with a high degree of probability. Incidental notice may here be taken of some springs which appear to boil, but are cold to the touch and to the thermometer. They are occasioned by currents of pure air or gases being in connection with their waters. There is one of this kind at Peroul, near Montpellier, which bubbles and heaves up furiously; and some parts of the river Etang, in the vicinity, exhibit the same appearance. Dr. Robinson found, in several dry places of the ground in that district, many small passages or clefts, at the mouth of which he placed light bodies, such as feathers, straws, and leaves, which were speedily blown aside. A remarkable spot was visited by Humboldt in South America, where phenomena of a class similar to those of the ebullient springs appeared-the eruption of water, mud, and air from the surface. The scene of this exhibition was near the Indian village of Turbaco, in the neighbourhood of Carthagena-a beautiful district adorned with luxuriant vegetation. After pushing his way through thickets of palm-trees, he reached an open space almost entirely devoid of verdure, called, by the natives, Los Volcanitos. They affirmed that, according to a tradition preserved in the village, the ground had formerly been ignited; but that a monk had extinguished it by frequent applications of holy water, and converted the fire volcano into a water volcano. The volcanitos consisted of several small truncated cones, having a height of about twenty feet, and their circumference at the base near eighty yards. At the top of each cone there was an aperture, about two feet in diameter, filled with water, through which air-bubbles obtained a passage. Each of the bubbles contained upwards of a cubic foot of elastic fluid; and their power of expansion was often so great, that the water was projected over the brim of the cone. Some openings by which air escaped were observed in the plain, without being surrounded by any prominence of the ground. The natives asserted that there had been no observable change in the form and number of the cones for twenty years, and that the little cavities are filled with water even in the driest seasons. The temperature of the water and mud was not higher than that of the atmosphere; the latter having been 81.5°, and the former 80·6° or 81°, at the time of Humboldt's visit. A stick could easily be pushed into the apertures to the depth of six or seven feet; and the dark-coloured clay or mud was exceedingly soft. An ignited body was immediately extinguished on being immersed in the gas collected from the bubbles, which was found to be pure azote. Here, botanising in the magnificent woods around, the traveller spent several happy days with Bonpland-the scientific companion of his journey, afterwards seized by the tyrant Francia-the subject of the following pleasing allusion, written in 1831: "At Turbaco we lived a simple and laborious life. We were young; possessed a similarity of taste and disposition; looked forward to the future with hope; were on the eve of a journey which was to lead us to the highest summits of the Andes, and bring us to volcanoes in action in a country continually agitated by earthquakes; and we felt ourselves more happy than at any other period of our distant expedition. The years which have since passed, not all exempt from griefs and pains, have added to the charms of these impressions; and I love to think that, in the midst of his exile in the southern hemisphere, in the solitudes of Paraguay, my unfortunate friend, M. Bonpland, sometimes remembers with delight our botanical excursions at Turbaco - the little spring of Torecillo- the first sight of a Gustavia in flower-or of the Cavanillesia loaded with fruits, having membranous and transparent edges." 6. Inflammable. Springs capable of firing and supporting flame are found in several parts of the globe, and, though not very numerous, they have been known from a very early era. They arise from combination with combustible substances of hydrogen gas. The substance usually found oozing out of the earth, in connexion with their waters, passes under the various names of pitch, naphtha, petroleum or rock oil, and bitumen. Naphtha is the purest state of this substance, which becomes petroleum upon a certain exposure to the air, and bitumen upon a continued exposure to it. The fountain by the temple of Jupiter, at Dodona, was inflammable, according to the account given of it by the Roman natural philosopher and poet Lucretius: "A fount there is, too, which, though cold itself, With instant flare the casual flax inflames Steering the course th' etherial breeze propels." Pliny confirms this representation; and if, with Colonel Leake, we suppose Dodona to have been in the valley south of the lake of Ioannina, in Epirus, the statement may be true; for now, in Illyria and Zante, at no great distance, there are pitch springs; and, in the latter, they were certainly in existence 2300 years ago, as we learn from Herodotus. "In Zacynthus," says the historian, "I saw pitch brought up out of the water of a pond. Indeed there are several of these ponds; but the largest of them is about seventy feet square, and twelve feet deep. The mode of procuring the pitch is the following:- They take a pole, and push it into the water with a myrtle branch at the end; and, on pulling it up, they find the pitch adhering to it, which in smell is like asphaltus, but of a better quality than the common pine pitch. They collect this pitch in a kind of vat or receptacle which they have dug near the pond; and, when the quantity is considerable, they put it in large jars or barrels." The historian might be describing an operation of the present day, so exactly do the proceedings of the modern Zanteotes correspond with his account. The great region of naphtha springs is to the west of the Caspian, in the territory of Baku, where a scene presents itself alike marvellous and unique. The naphtha streams spontaneously through the surface, and rises wherever a hole is bored. Speaking of a spot where it most abounds, Colonel Rottiers states: :-"It appears to undergo distillation as it ascends to the surface, and thence falls down the sides of the mountains into reservoirs, constructed at some unknown period. It is conjectured, that entire forests of resinous trees were once engulfed by some violent effort of nature, and that their decomposition is the origin of this inflammable liquid. The colour of the oil is black; but it shines with a reddish tint when the sun's rays are upon it." Not far from the same spot he observed a current of white oil gushing out, which readily inflames and burns upon the surface of water; and in calm weather the people of the country amuse themselves by pouring whole tons of it into a bay of the Caspian. They then set fire to it; and it is borne out of sight, giving the waves the appearance of a sea of fire; and, in comparison with this splendid exhibition, our finest illuminations and fireworks sink into insignificance. Petroleum springs occur in the territory of Modena and Parma, in Sicily, and in the Birman empire, where, in one locality, there are said to be upwards of five hundred wells, yielding annually 400,000 hogsheads. Around the island of Trinidad, also, fluid bitumen oozes from the bottom of the sea, and rises to the surface of the water; while, in the interior of the island, there is a vast collection of bituminous matter, forming a great pitch-lake, with frequent crevices and chasms filled with water. The origin of the substance in this locality is referred by some writers to the immense quan 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. 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, cold. 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 |