more especially muft the difference be feen, when compared with a part of the fame Mine under the fea, entirely free from fuch Water. The fubmarine ftrata of our Mines, muft be totally impervious to any Waters, which fall into the fea. It cannot be otherwife. So that fuch parts of the Mines, are quite free of any Water locally above them.

The next paradoxical confideration that occurs, is to account for the absence of the fuperfluent falt Water, from the fubmarine workings.

We have obferved a kind of flime or mucus upon fome marine ftrata, which is fo glutinous as to fill up every pore and cranny of the rock that is covered with it. This glutinous flime, we take to be a marine foil or earth, for the vegetation. of grafs, ore weed, and other fea plants; the fea is replete with it every fhip at the end of a long voyage has her bottom covered with it, and a marine grafs vegetates therein. This viscous matter thickens by degrees, as if purposely defigned to hinder the Water from penetrating into the earth; which it most effectually does, according to my judgment of the matter. Upon a rough beach, this flime may not be equally depofited, by means of the constant friction of rocky fragments under the action of the tide; and other parts may be covered with loofe fand and pebbles, which afford no bed or reft for this foil. In fuch case, it penetrates through the furface, and finds a quiet depofitory, in the fmall clefts and interfstices of the ftrata, below the force and action of the fea; and in time, probably, incruftates and fills up thofe very minute fiffures, with a petrifactive gluten, if it is at all charged with fuch principles; and we have neither theory or reafon to diffent from that opinion, as we think it must partake of every principle which is foluble by Air, Water, and Salt.

Thus have we demonftrated, that Top Water does not specifically defcend into the Mine where it falls upon the fea, and confequently that part of the Mine cannot be incommoded thereby like other parts; and that the minute pores and fiffures of fubmarine ftrata are almoft totally impenetrable by falt Water, through means of the petrifactive tenacious gluten, with which they are smeared. The facts, added to the compact, or close conformation of ftrata in fome parts of the earth under the sea, will ferve, as we prefume, for a proper folution of this difficult problem.

That

That there is a petrifying quality in the earth or its juices, is manifest to those who are converfant in Mining, and confider the nature of the Stones which are dug out of the ground; for they frequently meet with large folid rocks, compofed of several fmall Stones united together, of different forms, colours, and properties, with refpect to the fame individual Rock or Stone; which is a manifeft indication, that its different parts were originally loose and distinct from each other, until they were conjoined into an entire folid mass, by fomething of a petrifying principle, which cemented them together. It is more than probable that Stones, like Salts, and moft Foffils, are the productions of a fufpended lapidifick matter in a fluid, which gradually hardens into Stone, by the evaporation of its finer parts.

Mons. Tournefort obferves, "That in the famous labyrinth "of Crete, feveral perfons had engraved their names in the "rock, of which its walls are formed; and that the letters fo

engraven, instead of being hollow, as they were at first, stood "out from the furface of the rock." This can no otherwise be accounted for, than by fuppofing the cavities of the letters filled infenfibly with matter iffuing from the fubftance of the rock, even in more abundance than was needful to fill them. Letters cut hollow in a living rock of Limestone, fill up, in a courfe of years, with fpar; and what were made in Creux, are found in Relief. This has been seen in Gothland, by the eminent Swede. The spar ftands higher, as the time is more diftant; and has been feen, in fome places, a quarter of an inch above the level of the surface. (Hill)

Thus is the wound of a knife healed up, much as the fracture of a bone is consolidated, by a callus formed of the extravafated nutritious juice, which rises above the surface of the bone. Such cicatrixes have been obferved to be formed on other Stones, which were reunited, after they had been accidentally broken. The many inftances we have of thofe cicatrixes in Granite or Moorftone, upon the furface of every karn or karn or rocky hill in Cornwall and Devon, will clearly put this matter out of difpute; as our Stone-mafons always chufe fuch for fplitting in the very cicatrix, which generally is about a quarter of an inch above the other fuperficies of the ftone; and splits with more ease, than any other part of the fame block, because it was before feparated, and had been again reunited by its petrifactive gluten. Hence it is manifeft, that the fame juice which nourishes them,

It

ferves to rejoin their parts when broken. when broken. We find, that Water is fo full of ftony matter, and fo ready in part to turn into Stone, that it fills every crack and crevice of the moft folid rocks with Stone of the moft pure kind, Spar or Chrystal. If Water contains a quantity of ftony matter, then Water is able, in fome flow way and in the course of nature, to diffolve this ftony matter, though we cannot make it do fo in any of our operations. If Water can diffolve ftony matter, Water may take it out of one place of the carth, and carry it to another. will perhaps appear, that the original power of encrufting and petrifying lics in the earths and clays themselves, a thing few have thought upon; and that the Water ferves as a vehicle to carry the ftony matter out of one place into another. All this being understood, it feems natural to fuppofe, that not only the petrified fubftances found in the earth in fome places, but even the beds of Stones themselves, owe their origin to these particles contained in the earth, and to the agency of Water, which can diffolve, remove, difperfe, feparate, and bring them together again in various forms and combinations. If Water can diffolve thefe particles of ftony matter, Water can in the fame manner keep them fufpended for a time, and let them gradually separate and congeal afterwards. Water, therefore, can act, when it is thus loaded with particles, as a cement or agglutinating liquor to bind them together, or to introduce changes in them. For inftance, Water can fill the pores of clay; and if fuch Water fill the pores of a bed of this earth, and afterwards draining gently away, leave that ftony matter behind, it does, in that cafe, cement that bed of clay into a bed of Stone. (Owen).

This petrifactive quality, which ferves to conjoin and cement Stones together, we must allow capable of inclosing, within itself, fundry extraneous bodies, which it may be in contact with, fuch as bones, fhell-fish, and many other things, of which natural hiftory has given us fuch very ftrange accounts. I shall add a particular domestick instance, of which we have been very credibly informed: namely, that some few years fince, at this town of Redruth in Cornwall, fome labourers being put to clear and level the ftreet for a pavement, they found a piece of hard Stone in the ground, with abundance of common small pins of Brafs, interfperfed in and throughout the Stone, in such manner and form, that all those who faw it afterwards, were convinced, it was not done artificially, but that the Stone was formed and produced by petrifaction, fubfequent to the time the pins were dropped into the ground. Dr. Plot, in his Natural

History

Hiftory of Staffordshire, fays, "That near Newcastle under"line, there was found a Stone with a man's skull, teeth and all, inclosed in it !"

:

From what has been faid, I prefume it may not be abfurd to infer, that every earth or clay, in fome places, may be converted to Stone in procefs of time, at fuch a depth where it is undif turbed, by being never lacerated nor molefted; and alfo where it abounds with an uncommon quantity of juices, of a lapidescent quality but this property being extenuated or destroyed, the earthy Stones may, not improbably, again return to their primitive earth or clay. Thus we fee fome forts of Stone, when dug out of the ground, and exposed to the air for a confiderable time, do moulder again to earth, at leaft in appearance; while others, of an earthlike quality, are indurated, and become more compact and durable, by lying above ground. Hence fome have imagined, that all the terreftrial globe, and every individual inanimate thing contained in it, is nothing else but Water, rendered solid by petrifaction.

Thales, the Milefian, held Water to be the first principle of all natural bodies, of which they confift, and into which they refolve. He endeavours to establish this opinion, by arguments drawn from the origin and continuation of most things: first, because the feminal and generating principle of all animals, is humid; and secondly, because all kinds of plants are so much nourished by Water, that when they want moisture, they wither and decay. Some have not hesitated to father this philofophy on Moses. The great prince of philofophers, Aristotle, with Lucretius, Theophraftus, and Leonardus, were of the fame opinion. Nay, Hippocrates lays great ftrefs upon it; and of later days the great Sendivogius, with the most learned of the Spagyrifts, who own that Water is an universal principle.

This Crystalline or lapidifick juice, Mons. Geoffroy fays, is more heavy and fixed than fimple Water; and confequently is not evaporated with it, but is left behind: and thus the formation of Crystal is perfectly like that of the Crystals of falts. For these Crystals only arife with those regular figures they affect, as when a Water impregnated with falts is flowly evaporated at perfect reft in a moist place. The evaporation of the Water is neceffary, that it may not keep the falts too far asunder; and the flowness of the evaporation, that the falts may have time to take that arrangement, which agrees best with their

H

their respective figures. The application of this to Rock Cryftal, is obvious: it is only needful to conceive, that a Water charged with a quantity of Crystalline juice, had infinuated itfelf through the clefts of fome Rock, where the aqueous part gradually evaporated.

An unfaline Crystal earth, though not in fuch plenty as a faline, is yet as intimately mixed in Water, nay in the fulleft degree of clearness paffes through the clofeft ftrainers; confequently, the cryftallization of falt is here not improperly alleged for a model or pattern. (Henckell.)

It must be confidered, that this Cryftalline juice is not equally diffused in all parts of the Mine; fo that Rock Crystal would not arise in all places, even fetting afide the neceffity of other concurrent circumftances, which do not often meet. If the Water impregnated with Cryftalline juice happens to penetrate a mass of earth, which is the most usual cafe, it will connect and bind together the parts thereof by means of this juice; and afterwards, in proportion as the watery part evaporates, the compound will grow harder, and at last become Stone. Add to this, that it will approach nearer to the nature of Crystal, that is, it will be more hard and tranfparent, according as the quantity of that juice is greater; and at the fame time have a finer grain, according as the molecules of the earth are smaller and more homogeneous. Of this kind are Marbles and Alabafters; in fome of which, one may difcern threads or veins, as transparent as if they were wholly Crystal. The Stones moft oppofite hereto, and moft imperfect, are Chalk and Boles, which are little elfe befides earth ill bound together, with a very fmall proportion of Crystalline juice, which leaves them ftill friable. Between thefe, it is eafy to imagine, there are infinite degrees.

Camillus Leonardus fays, that "Stones which abound most "with the terrene, are thick and dark; neither are they free "from Water. And Ariftotle, in his book of Minerals, expreffly fays, "Pure earth doth not become a Stone, because "it makes no continuation, but a brittleness; the prevalent "drinefs in it, permits it not to conglutinate; and fo by the

aqueous mixed with the terrene, Stones are made.' By the aqueous, he means an unctuous or viscous humidity, proportioned with a terrene; and according to the difpofition or proportion

of