jacent countries.

Earthquakes have not been experienced for many years in those parts; but foon after the French first fettled in Canada, very tremendous ones were felt. Dr. Hutton will then allow it poffible, that an earthquake may even at once effectuate the deftruction of the whole mound which now fuftains lake Erie. It is devoutly to be hoped that fuch catastrophe may not take place, as in that cafe lake Ontario and the river St. Lawrence would be fo fwelled as to overflow all the countries around them, to the probable destruction of their now numerous inhabitants. But fhould this head be, either gradually in the course of many centuries, or by convulfion at once, fuddenly difrupted, it is evident that the lake above it, and all the great western lakes communicating with it, would be fucceffively or inftantly drained either of the whole or of great part of their waters. Their beds would then exhibit either much diminished lakes, or valleys, in a fhort time not unfruitful, traverfed by one or more rivers. In a certain term of years, no other natural proofs would remain of the existence of former lakes than fuch traces as are now difcoverable in the paffages of the Potowmac and Delaware rivers, and in the countries below them. Such furely may be the very natural fate of every lake fufpended high above the general level, without the neceffary intervention of millions of years. In times immediately subsequent to the deluge, when all nature was yet in the full paroxyfm of convulfion, it is more than probable that fuch unrecorded accidents did happen; and to fuch many actual appear ances must be referred.

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From the obfervations I have made, particularly on the afcents of Mount Jura from Franche Comté, the bafons of many formerly-existing lakes are very likely to have been frequently mistaken for the remnants of volcanos by those philofophers who, prepoffeffed with the idea of finding every where their traces, have without hesitation adopted them as the craters of antient eruptions. Extenfive level plains, although in a circular form, furrounded by moderate, eminences broken down in one part only, and

that

that always towards the defcent, prefent, however, very different aspects from the mouths of volcanos. On this afcent of Mount Jura many of thefe of various extent, but lefs fpacious towards the fummit, are to be remarked one above another. The breaking down of the mounds of one of thefe uppermost lakes would neceffarily occafion the rupture of all the lower refervoirs thus fuddenly overcharged, nearly, as it appears to have happened, in the fame direction. I do not know that there are any volcanic appearances on the fides of these basons; but, if there were, it would not exclude their formerly being filled with water, which their remarkably level bottoms without any tunnel-like appearance clearly indicate. In the neighbourhood of fo much water favourable to the kindling of volcanic fires, earthquakes may have contributed to break down their banks. That affiftance feems, however, neither neceffary nor probable, from the abovementioned fimilar direction of the ruptures. Thefe delightful oval or circular meadows, encircled by floping banks covered with wood, repeated at various ftages, form the most beautiful and pleafing variety I ever beheld. I have no doubt but many fuch emptied bafons of former lakes, very natural to have exifted after a general inundation, and to have dif appeared from the confequences of various accidents at various times, are frequently taken for volcanic craters by thofe who have adopted the fyftem of formation by fire. The attribution of many of these to water excludes not, however, frequent and undoubted indications of volcanic fires. The multiplicity of waters in the early periods fucceeding the deluge make thefe but the more probable, and both are likely to have then exifted in countries where neither lakes nor volcanos now remain.

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Mr. Monnet in his Mineralogy affures us, that a great cavity filled with water, when a certain gallery in the mines of Sainte Marie aux Mines in Alface was abandoned, was found, after 50 years when that gallery was again opened, filled with transparent quartz. As Mr. de Buffon informs us, there is a fpecies of earth on the Pharos of Meffina which petri

fies with astonishing rapidity. To form it into mill-ftones, no other opera tion is neceffary but, after having cleared away about two feet of foil, to kneed the under-ftratum and form it into the shape required, and then cover it loofely again with the fame foil. In a year's time the mill-stone is found perfectly hardened. The hardness of coble and pebble stones occafions them to be generally looked upon as ftones of very antient petrification: this is, however, often not the cafe. In the dried bed of a torrent in Italy, I remember to have gathered in a short time, as I walked along it, a number of fpecimens of pebbles of very different degrees of hardness and formationfrom that which still received the impreffion of the finger, or easily crumbled when preffed, to that degree which furpaffes the hardness of most other kinds of stones. These new-moulded pebbles, frequently interfected by veins of different colours, perfectly resembled others in the completeft degree of induration. Clays, thus rounded and gradually hardened, are easily to be found in the bed of every torrent exposed to be fometimes filled with waters, and at other times laid dry. The petrifying qualities of many waters are too well known to be infifted upon. One inftance of the abundance and minutenefs of ftony particles contained in waters, and of the celerity with which they fuperinduce a ftony incruftation, is worthy to be recorded. It is mentioned by Mr. Dietrich, the late philofophic mayor of Strasburg, and inferted by Mr. de Buffon in his Natural Hiftory of Minerals. By the ingenious management of the waters of Santo Filppo on the mountain Santa Fiora near Sienna, Doctor Leonardo Vegni has contrived, to take off the impreffion of medals and baffi relievi, by incruftation; even casts have been taken from buftos, and he hopes at length to be able to take off whole ftatues. Any porous fubftances may be impregnated both inwardly and outwardly with these sediments; and if the animal or vegetable fubftance which ferves as a mould fhould decay, the remaining concretion will appear a true petrification of the body itself, though it has really been only incrufted, interiorly as well as exteriorly. If woods or fhells are thrown into these quickly-accumulating concretions, they will be as completely petrified within them, as we fometimes find fuch fub

ftances

ftances in fofil bodies. By a diffolution of fernambuco wood, the doctor gives various colours to these petrifications. Thus thefe great interpreters of nature cannot help acknowledging the extreme promptitude of her actual proceffes on a small scale, whilft they difavow the poffibility of a like celerity in her primæval powers of concretion on a larger; because it would militate against their favourite fyftem, of flow operations during an infinity of ages.

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It is well known that artificial ftones, perfectly refembling in appearance and folidity Portland ftone, have been long fabricated in London. Variegated alabasters, jaspers, and agates, are crystallized at Ashbourne and other places. The art of man has not yet been able to give their genuine luftre or folidity to the imitations of diamonds and the finer precious ftones; but all other kinds of ftones are imitated to a degree of perfect deception by a hundred artists in every part of Europe. Shall plastic Nature in her fullest vigour, the goddess whom fome philofophers alone adore, or the omnipotent God of Nature herself, require thousands and ten thousands of years to complete the originals, however greatly they may furpass the imitations?

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The crystallization, or what is called the vegetation, of lead in water by zinc is but lately discovered. Sugar of lead in water is fo powerfully and quickly attracted by a piece of zinc, that in a few hours the whole forms a beautiful arborization pendent in the bottle from that matter. Such crystallizations are alfo effected by fire. Mr. Ferber obferves, that various shorl crystallizations are formed in the empty bubbles of the torrents of lava, cooling on the fuperficies whilft yet in violent fufion underneath. Diamond-like crystallizations are likewife formed in it, though much inferior in hardness, in regularity, and brightness of colours, to real gems which are cryftallized in water. When the whole earth was yet a liquid pulp

fwimming in every kind of menftruum, actuated upon by the great mass of universal light, and when dry land appeared, by the full force of its ruling fun, how can we fuppofe that these fame laws of nature in their fullest vigour fhould require thousands of years to cryftallize or coagulate the various fubftances of which we fee it now compofed? What these watery menftrua did not effect, frequent volcanic fires-natural in the first great fermentation of matter, either immediately after the creation or after the deluge, when its exterior coat was nearly reduced to the fame fituationmight well bring to perfection during the first four centuries, when men were yet confined to a narrow spot. That at this laft epoch its whole exterior surface was convulfed, diflocated, and diffolved, every monument of nature amply teftifies. God had faid that he would deftroy not only the whole impious race of men but the earth with them; and he afterwards promifes Noah that there fhall not be another deluge" diffipating," according to the literal words of the Hebrew; according to the Samaritan verfion "fcattering," or " difperfing" tranflated by the Greek" to cor"rupt," or "disfigure," and by the Syriac and Arabic "to destroy" the earth; that is to fay, fince the body of the globe remained, its outward form and furface.

THOUGHTS