A Walk to the Incrusting Springs.—The so-called "petrifying springs and wells" of Derbyshire are celebrated throughout England for the incrusted birds’ nests, baskets, &c. which are very generally purchased by visitors, as mementos of a trip into this county. The nature of this deposition of calcareous matter has already been explained (see p. 39; and Wond. p. 75); and, although the objects above mentioned are scarcely worthy of notice, the natural operations by which the tufa and travertine are produced, are extremely interesting.[799]
[799] If the proprietors of these springs could be induced to follow the example of the Italians at San Filippo (see Wond. p. 75), or of the French, in Auvergne, or the Germans at Carlsbad, elegant bas-reliefs and other beautiful objects might be obtained, for the incrusting power of the Matlock waters is very considerable.
Our first stroll shall therefore be to the beds of tufa which have been formed in remote ages by this operation and which now constitute the terrace on which the Old Bath and two other hotels, and the elegant modern Church are situated. Proceeding from our Inn, the tufaceous rock may be seen protruding in masses on the right hand, in front of the beautiful parterres of the hotels; and upon crossing the road, where a narrow path leads down to the bed of the river, and nearly opposite to the new church, the lower beds of tufa are exposed in a quarry, from which large blocks of the coarse, porous stone are extracted for grotto and rock-work. From this spot I collected very fine impressions of the foliage of the oak, elm, and hazel, leaves of adder’s tongue (scolopendrium), &c. and large portions of moss, beautifully incrusted.[800]
[800] I could not obtain any specimens of this kind from the quarry-men nor from the shops or museums, as they are termed; such objects not being deemed "curiosities" by the good folks of Matlock; and the workmen forbade me to search for more in the quarry!
The origin of this deposit of tufa, which covers so huge an area along the western flank of the mountain range of Masson Hill, is attributable to the thermal springs having, at some very remote period, issued from a much higher source than at present, and flowing down the side of the hill into the river at its foot, the water, as it cooled, deposited the lime with which it was charged on the stems, branches, leaves, and other extraneous bodies. At this time the springs escape from crevices in the rocks at an elevation of about one hundred feet above the bed of the river; the waters, at their source, have a temperature of from 66° to 68°, and contain free carbonic acid and minute quantities of muriates and sulphates of magnesia, lime, and soda. Their origin is now concealed, and the water conducted by pipes to the various baths and fountains; but wherever a rill escapes, and flows down the hill, the moss, &c. is quickly incrusted. I was informed, that in about eight mouths a basket of eggs would be entirely enveloped in a thick mass of tufa. The uniform high temperature of these waters shows that they emanate from a very deep source; and it is probable that they originate from steam, which is cooled and condensed as it approaches the surface of the earth. The miners assured me, that the springs burst out from beneath the volcanic rock, here termed toadstone, and that the water, when it first issues, is of a higher temperature than the Matlock Bath water; but its heat is reduced by the cool land-springs with which it becomes intermingled.
Most waters that flow through limestone districts deposit travertine more or less abundantly; and I observed several streams in my rambles in the neighbourhood of Matlock which appeared to possess this property in as great a degree as the thermal springs. There is a lovely waterfall, which issues from the side of a mountain that flanks the road leading by Via Gellia to Middleton Moor, at an elevation of two hundred feet, and flows into the adjacent valley, bounding and dancing from one mossy knoll to another, and appearing from the opposite hill like a stream of molten silver, undulating through a carpet of emerald green. The waters of this cascade have formed a thick bed of travertine along the side of the hill; and the stone is of so firm a texture, that the walls of a cottage hard by are constructed of it.
I gathered from the banks of this waterfall, bundles of moss and groups of small shells incrusted with a beautiful white tufa; and impressions of leaves, twigs, &c. were observable in the blocks of travertine recently quarried.
In contemplating the effects produced by these limpid streams, by which perishable leaves and fragile shells are preserved for ages in solid masses of rock, we are reminded of the forcible and eloquent remarks of Sir Humphry Davy, when observing similar phenomena in the volcanic regions of Italy. "How marvellous are those laws, by which even the humblest types of organic existence are preserved though born amidst the sources of their destruction; and by which a species of immortality is given to generations, floating, as it were, like evanescent bubbles on a stream raised from the deepest caverns of the earth, and instantly losing what may be called its spirit in the atmosphere!"[801]
[801] "Consolations in Travel; or, the Last Days of a Philosopher;" by Sir Humphry Davy. See also Wond. p. 77.