during the shocks at the borders of the wells in the plain of Charas. Water and sand are sometimes thrown out twenty feet high. Similar phænomena have not escaped the observation of the ancients, who inhabited parts of Greece and Asia Minor abounding with caverns, crevices, and subterraneous rivers. Nature, in its uniform progress, every where suggests the same ideas of the causes of earthquakes, and the means by which man, forgetting the measure of his strength, pretends to diminish the effect of the subterraneous explo. sions. What a great Roman naturalist has said of the utility of wells and caverns is repeated in the New World by the most ignorant Indians of Quito, when they show travellers the guaicos, or crevices, of Pichincha.

The subterraneous noise, so frequent during earthquakes, is generally not in the ratio of the strength of the shocks. At Cu mana it constantly precedes them, while at Quito, and for a short, time past at Caracas, and in the West India Islands, a uoise like the discharge of a battery was heard, a long time after the shocks had ceased. A third kind of phæ nomenon, the most remarkable of the whole, is the rolling of those subterraneous thunders, which last several months, without being accompanied by the least oscillating. motion, of the ground.

In every country subject to earthquakes, the point where, probably, by a disposition of the stony struta, the effects are the most sensible, is considered as the cause and the focus of the shocks. Thus at Cumana the hill of the castle of St.

Antonio, and particularly the eminence on which the convent of St. Francis is placed, are believed to contain an enormous quantity of sulphur, and other inflammable matter. We forget, that the ra pidity with which the undulations are propagated to great distances, even across the basin of the ocean, proves, that the centre of action is very remote from the surface of the Globe. From this same cause no doubt earthquakes are not restrained to certain species of rocks, as some naturalists pretend, but all are fitted to propagate the movement. In order to keep within the limits of my own experience, I shall here cite the granites of Lima and Acapulco; the gneiss of Caracas; the mica-slate of the peninsula of Araya; the primitive thonschiefer of Tepecuacuilco, in Mexico; the secondary limestones of the Appennines, Spain and new Andalusia and finally the trappean porphyries of the provinces of Quito, and Po payan, In these different places the ground is frequently agitated by the most violent shocks; but sometimes in the same rock, the superior strata form invincible obstacles to the propagation, of the motion, Thus, in the mines of Saxony, we have seen workmen hasten up,affrighted by oscillations, which were not felt at the surface of the ground.

If, in regions the most remote from each other, primitive, secon dary, and volcanic rocks, share equally in the convulsive move ments of the Globe; we cannot but admire also, that in ground of little extent, certain classes of rocks op pose themselves to the propagation of the shocks. At Cumana for in

stance, before the great catastrophe of 1797, the earthquakes were felt only along the southern and calcarious coast of the gulf of Cariaco, as far as the town of this name; while in the peninsula of Araya, and at the village of Maniquarez, the ground did not partake of the same agitation. The inhabitants of this northern coast, which is composed of mica-slate, built their huts on a motionless earth; a gulf three or four thousand toises in breadth separated them from a plain covered with ruins, and overturned by earthquakes. This security, founded on the experience of several ages, has vanished; and since the 14th of December, 1797, new communications appear to have been opened in the interior of the globe. At present the peninsula of Araya is not merely subject to the agitations of the soil of Cumana, the promontory of mica-slate is become in its turn a particular centre of the movements. The earth is sometimes strongly shaken at the village of Maniquarez, when on the coast of Cumana the inhabitants enjoy the most perfect tranquillity. The gulf of Cariaco nevertheless is only sixty or eighty fathoms deep.

It has been thought from observations made both on the continent and in the islands, that the western and southern coasts are most exposed to shocks. This observation is connected with the ideas which geologists have long formed of the position of the high chains of mountains, and the direction of their steepest declivities; the existence of the Cordillera of Caracas, and the frequency of the oscillations on the eastern and northern coasts of

Terra Firma, in the gulf of Paria, at Carupano, at Cariaco, and at Cumana, are proofs of the uncertainty of this opinion.

In New Andalusia, as well as in Chili and Peru, the shocks follow the course of the shore; and extend but little inland. This circumstance, as we shall soon find, indicates an intimate connection between the causes that produce earthquakes and volcanic eruptions. If the earth was most agitated on the coasts, because they are the lowest part of the land, why should not the oscillations be equally strong and frequent on those vast savannahs or meadows, which are scarcely eight or ten toises above the level of the ocean?

The earthquakes of Cumana are connected with those of the West India Islands; and it has even been suspected, that they have some connection with the volcanic phænomena of the Cordilleras of the Andes. On the 4th of November, 1797, the soil of the province of Quito underwent such a destructive commotion, that, notwithstanding the extreme feebleness of the population of that country, near 40,000 natives perished, buried under the ruins of their houses, swallowed up in the crevices, or drowned in lakes that were suddenly formed. ' At the same period, the inhabitants of the eastern Antilles were alarmed by shocks, which continued during eight months, when the volcano of Guadaloupe threw out pumice stones, ashes, and gusts of sulphureous vapours. This eruption of the 27th of September, during which very long continued subterraneous noises were heard, was followed on

the 14th of December by the great earthquake of Cumana. Another volcano of the West India Islands, that of St. Vincent's, has latelygiven a fresh instance of these extraordinary connections. This volcano had not emitted flames since 1718, when they burst forth anew, in 1812. The total ruin of the city of Caracas preceded this explosion thirtyfive days, and violent oscillations of the ground were felt, both in the islands, and on the coasts of Terra Firma.

It has long been remarked, that the effects of great earthquakes extend much farther than the phanomena arising from burning volcanoes. In studying the physical revolutions of Italy, carefully examining the series of the eruptions of Vesuvius and Etna, we can scarcely recognize, notwithstanding the proximity of these moun tains, any traces of a simultaneous action. It is on the contrary doubtless, that at the period of the last and preceding destruction of Lisbon, the sea was violently agitated even as far as the New World, for instance, at the island of Barbadoes, more than twelve hundred leagues distant from the coasts of Portugal.

Several facts tend to prove, that the causes which produce earthquakes have a near connection with those that act in volcanic eruptions. We learn at Pasto, that the column of black and thick smoke, which, in 1797, issued for several months from the volcauo near this shore, disappeared at the very hour, when, sixty leagues to the south, the towns of Riobamba, Hambato, and Tacunga were overturned by an enormous shock.When, in the interior of a burnVOL. LVI.

ing crater, we are seated near those hillocks formed by ejections of scoriæ and ashes, we feel the motion of the ground several seconds before each partial eruption takes place. We observed this phænomenon at Vesuvius in 1805, while the mountain threw out scoriæ at a white heat; we were witnesses of it in 1812, on the brink of the immense crater of Pichincha, from which nevertheless at that time clouds of sulphureous acid vapours only issued.

Every thing in earthquakes seems to indicate the action of elastic fluids seeking an outlet to spread themselves in the atmosphere.Often, on the coasts of the South Sea, the action is almost instantaneously communicated from: Chili to the gulphof Guayaquil, a distance of six hundred leagues; and, what is very remarkable, the shocks appear to be so much the stronger, as the country is more distant from burning volcanoes. The granitic mountains of Calabria, covered with very recent breccia, the calcareous chain of the Apennines, the country of Pignerol, the coasts of Portugal. and Greece, those of Peru and Terra Firma, afford striking proofs of this assertion. The globe, it may be said, is agitated with greater force, in proportion as the surface has a smaller number of funnels communicating with the caverns of the interior. At Naples and at Messina, at the foot of Cotopaxi and of Tunguragua,earthquakes are dreaded only when vapours and flames do not issue from the crater. In the kingdom of Quito, the great catastrophe of Riobamba, which we have before mentioned, has led several wellinformed persons to think, that

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this unfortunate country would be less often desolate, if the subterraneous fire would break the porphyritic dome of Chimborazo; and if this colossal mountain should become a burning volcano. At all times analogous facts have led to the same hypothesis. The Greeks, who, like ourselves, attributed the oscillations of the ground to the tension of elastic fluids, cited in favour of their opinion the total cessation of the shocks at the island of Eubœa, by the opening of a crevice in the Lelantine plain.

An Account of a Family having

Hands and Feet with supernumerary Fingers and Toes. By ANTHONY ČARLISLE, Esq. F. R. S. In a Letter addressed to the Right Hon. Sir JOSEPH BANKS, Burt. - K.B. P.R.S.-(From the Philo sophical Transactions for 1814, part i.)

DEAR SIR,-The following account of a family having hands and feet with supernumerary fingers and toes, and the hereditary transmission of the same peculiarity to the fourth generation, appears to be worth preserving, since it displays the influence of each of the propagating sexes; the male and the female branches of the original stem having alike reproduced this redundancy of parts. I have carefully inspected two persons of this family at the time of their being in London, namely, Abiah Colburn, and his son Zerah Colburn, and have taken the particulars of the rest from Abiah Col'burn himself, whose narrative was several times repeated to me, with out any dev deviation.

Zerah Colburn, a native of the

township of Cabot in the province of Vermont, in North America, has been lately brought to London, and publicly exhibited for his extraordinary powers in arithmetical computations from memory. This boy has a supernumerary little finger growing from the outside of the metacarpus on each hand, and a supernumerary little toe, upon the outside of the metatarsus of each foot. These extra fingers and extra toes are all completely formed, having each of them three perfect phalanges with the ordinary joints, and well shaped nails. Zerah, has five fingers and a thumb Abiah Colburn, the father of upon each hand, and six toes on each foot; he has also five metaCarpal bones in each hand, and six metatarsal bones in each foot. The extra limbs have distinct flexor and extensor tendons.

Four of those sons

The wife of Abiah Colburn has no peculiarity in her limbs, During the existing marriage, she has borne eight children, six sons, and two daughters. inherit the peculiarity of their father more or less complete, while the two daughters are free from the family mark, as well as two of the sons, namely, the fourth in succession who was a twin, and the eighth.

The eldest son of these parents, named Green Colburn, has only five toes on one of his feet, but the other foot and both his hands possess the extra limb.

The second child, Betsy Colburn, is naturally formed.

The third, Zebina Colburn, has five fingers and a thumb upon each hand, and six toes upon each foot.

The fourth and fifth are twin brothers, and named David and

Jonathan; David, who is dead, had nothing of the father's mark,

but

Jonathan has the peculiarity complete.

The sixth, Zerah Colburn, the extraordinary calculating boy, is marked like his father, as before described.

The seventh, Mary Colburn, is naturally formed.

The eighth and last child, Enas Colburn, is also exempt from the father's peculiarity.

Besides the persons I have men. tioned, this hereditary redundance of limbs has been attached to the little fingers and to the little toes of several of the ancestors of the family. The mother of Abiah Colburn brought the peculiarity into his family. Her maiden name was Abigail Green: she, however, had not the extra finger on one of her hands; the other hand and her feet were similarly marked with those of her son Abiah.

David Colburn, the father of Abiah, had no peculiarity. By his marraige with Abigail Green, he had three sons and one daughter. Two of these sons and the daughter were fully marked in all the limbs; the other son had one hand and one foot naturally formed.

Abigail Green inherited these -supernumerary limbs from her mother, whose maiden name was Kendall, and she had five fingers and a thumb upon each hand, and six toes on each foot. The marriage of Kendall with Mr. Green produced eleven children, whom Abiah Colburn's mother, who was one of the eleven, reports to have been all completely marked: but the pre-sent family are unacquainted with

the history of the other ten branches, and they do not possess any knowledge of their ancestors beyond

Kendall, the great grandmother of Zerah Colburn,

Numerous examples of the hereditary propagation of peculiarities have been recorded: all family resemblances, indeed, however trifling they may appear to a common observer, are interesting to the physiologist, and equally curious; though not so rare as those describ, ed in the preceding history, lo every department of animal nature, accumulation of facts must always be desirable, that more reasonable inductions may be established concerning the laws which direct this interesting part of creation and it might be attended with the most important consequences, if discovery could be made of the relative influence of the male and female sex in the propagation of peculiarities, and the course and extent of hereditary character could be ascertained, both as it affects the human race in their moral and physical capacities, and as it governs the creatures which are subdued for civilized uses. Nor is it altogether vain to expect that more profound views and more applicable facts await the researches of men, who have as yet only begun to explore this branch of natural history, by subjecting it to physical rules.

Though the causes which govern the production of organic monstrosities, or which direct the hereditary continuance of them, may for ever remain unknown, it still seems desirable to ascertain the variety of those deviations, and to mark the course they take, where they branch out anew, and where