army wherever they went; he was, however, victorious.

In the year 56, he advanced, at one push, on Nantes and Vannes, detaching corps of considerable strength into Normandy and Acquitain. The nearest point of his depots at that time was Toulouse, from which place he was distant 130 leagues, and separated by mountains, great rivers, and forests.

In the year 55, he carried the war to Zutphen, in the interior of Holland, where 400,000 barbarians were passing the Rhine to take possession of the islands of the Gauls; he defeated them, killing the greater part, and driving the others to a considerable distance. He then repassed the Rhine at Cologne, crossed Gaul, embarked at Boulogne, and made a descent in England.

In the year 54, he once more crossed the channel, with five legions, conquered the banks of the Thames, took hostages, and returned into Gaul before the equinox. In autumn, having received intelligence that his lieutenant, Sabinus, had been slaughtered near Treves, with 15 cohorts, and that Quintus Cicero was besieged in his camp at Tongres, he assembled 8000 or 9000 men, commenced his march, defeated Ambiorix, who advanced to meet him, and relieved Cicero.

In the year 53, he suppressed the revolt of the people of Sens, Chartres, Treves, and Liege, and passed the Rhine a second time.

The Gauls were already in agitation, the insurrection burst forth on every side. During the winter of 52, the whole population rose; even the faithful people of Autun took part in the wars. The Roman yoke was odious to the people of Gaul. Cæsar was advised to return into the Roman province, or to repass the Alps; he adopted neither of these plans. He then had 10 legions; he passed the Loire, and besieged Bourges, in the depth of winter, took that city, in the sight of the army of Vercingetorix, and laid siege to Clermont; he failed, lost his hostages, magazines, and horses; these were at Nevers, the place of his depot, of which the people of Autun took possession. Nothing could appear more critical than his situation. Labienus, his lieutenant, was kept in alarm by the people of Paris; Cæsar ordered him to join him, and, with his whole army in junction, laid siege to Alesia, in which town the

Gallic army had enclosed itself. He occupied 50 days in fortifying his lines of countervallation and circumvallation. Gaul raised a new army, more numerous than that which she had just lost; the people of Rheins alone remained faithful to Rome. The Gauls arrived to compel him to raise the siege; the garrison united its efforts with theirs during three days, in order to destroy the Romans in their lines. Cæsar triumphed over all obstacles; Alesia fell, and the Gauls were subdued.

Cæsar availed himself of his victory to regain the affections of the people of Autun, amongst whom he passed the winter, although he made successive expeditions, at 100 leagues distant from each other, with different troops. At length, in the year 51, he laid siege to Cahors, where the last of the Gallic army perished. The Gauls became Roman provinces, the tribute from which added to the wealth of Rome eight millions of money annually. [To be continued.]

BIOGRAPHY.

THE LATE LORD ERSKINE. The death of this eminent person has produced a sensation of mournful kindness and high estimation, as honourable to his memory as it is decisive of his fame. The palm of public virtue and public talent is rarely deposed, without a voice of dissent or rivalry, even upon the grave. There is something peculiarly fortunate in the eminence which Lord Erskine attained. The first talents of the nation-minds of at least equal power and of as deep, and varied learning,-had undoubtedly preceded him in the career of the Bar; yet is it his fortune and his merit to have first introduced oratory into our Courts of Law; to be himself not only the first example, but the most accomplished and the greatest, and to maintain his supremacy, amidst a host of contemporary and succeeding talent, through many years of retirement. Never did man make a happier use of his faculties, his endowments, and his occasions. His eloquence may be characterised as the eloquence of art and temperament, rather than of genius, Nature passion, and imagination. seems to have endued him with a right

read with advantage to the reader and justice to the speaker. Lord Erskine had one disqualification for one aspiring to the first place as an orator. He was, no doubt, acquainted with the ancients, but he was unimbued with their spirit. He quoted poetry and made allusions of historical fact. But this is not sufficient. Grattan never quoted-but he parodied to his use, not only Demosthenes, but Virgil. It is delightful to the scholar to recognize in Fox's speeches the orator's recollections not only of Demosthenes, but of Sophocles and Homer. Curran had made his finest exordium by imitating that of the oration for Milo. The grace and force of these classical reminiscences are felt by all-even by those who do not know the sources whence they are derived. When Lord Erskine would be classical, he merely alluded to Cicero and Verres, before a jury who had then, perhaps, heard those names for the first time. It was not our fortune to hear Lord Erskine at the bar, or in the House of Commons. His supremacy failed him in the House of Peers. He never, it is said, recovered the first blow received by him in the House of Commons. The haughty minister of that day bore him down, in the first onset, with sarcasm, disdain, and declamation; but the reason is obvious-his eloquence is that of temperament, and it failed him when no longer in sympathy with a strictly popular tribunal. He has left behind him some pamphlets, and a sort of political romance. The latter is forgotten already. It might be interesting as a memorial of the leisure of a great man, from graver and higher studies. His pamphlets have much of that eloquence of temperament which we have ascribed to his speeches; but he has left behind him another legacy, more valuable, and more noble than any to which we have yet alluded-the shining example of his professional and public life.

SCIENCE.

ORIGIN OF VOLCANOES. M. Guy Lussac has given a long and somewhat speculative paper in the Ann. de Chim. tom. xxii. on the probable origin of volcanic irruptions. Discarding the agency of permanent fires within the interior of the earth, he ascribes volcanic irruptions to chemical

agency only-in other words, to the agency of air and water acting on the metalic and earthy matters within the crater of the volcano. In almost every instance of volcanic irruption we have evidence of vast quantities of water having been employed, by the enormous masses of aqueous vapours which are discharged with the smoke previous to the issue of red-hot lava; which aqueous vapour is again condensed by cold in the form of rain on the summit of the mountain, and frequently accompanied by tremendous thunders and lightning: as was witnessed in the dreadful eruption of Vesuvius, which destroyed Terre del Greco in 1794.

The water of volcanoes is derived from the sea. It is easy to conceive, that if the cavern of a volcano extend beneath the bed of the sea-shore, the fissures or crevices which would be produced in the sides of such cavern by any violent explosion, would be the means of producing future irruptions by allowing the water to percolate through such fissures; and, either by the chemical agency of its action in the metallic cases and earths which constitute the mass of the lavas, or merely by its mechanical agency when converted into steam, it will produce the powerful effects witnessed in volcanic irruptions. Mr. Guy Lussac seems to refer this immense agency to the decomposition of water, and the consequent new combinations its constituents, oxygen and hydrogen, form with the metallic earths, producing what are now known to be oxides, as alumina, silica, lime, soda, pot-ash, and oxide of iron, all which substances are found in the lava or scoria of a volcano. Although M. Lussac witnessed several irruptions of Vesuvius in 1805, which projected the lava to the height of two hundred toises, he could not discover the inflammation of hydrogen gas; which, according to his view, ought to have been disengaged uncombined; the oxygen of the water having incorporated with the earthy bases. But we apprehend the production of the thunder before-mentioned ought to be ascribed to the hydrogen gas; and this gas (as was suggested in a former number of the Literary Museum) probably forms the basis of thunder on all occasions. But M. Lussac must have known that hydrogen gas will not burn or inflame unless in contact with, a considerable portion of oxygen; and it is difficult

to imagine that the atmosphere immediately over the summit of a volcano should contain much oxygen. Even in a state of repose, the air in contact with the crater of Vesuvius is described by every traveller as so far charged with sulphureous and carbonic vapour as to render it incapable of respiration. But at the time of an irruption, the column of air immediately over the cone we should consider as almost entirely deprived of its oxygenous portion, by the sulphur-carbon and metallic vapours which are escaping in a state of sublimation. It is true M. Lussac denies the presence of sulphur in volcanoes: but we apprehend he cannot deny its presence in the soil, and in innumerable grottoes or caverns in the peninsula of Italy and the adjacent volcanic islands. He whimsically illustrates his theory of earthquakes by the vibration produced on a long beam, by striking one of its ends with a pin's head! We are of opinion, so able a chemist might have produced a greater effect, even on the French lavas, if he had chosen a grander simile for such stupendous natural agency.

ON MARKING THE AGE OF

THE OAK.

In Clipstone Park, in Nottinghamshire, is an oak called the Parliament Oak, from a tradition of a Parliament having been held there by King Edward I.-Near Blidworth, there is a large and ancient elm, called Langton Arbour, which even some centuries ago, was sufficiently remarkable to give a name to one of the forest walks, and to have a keeper appointed to it. Major Rooke tells us, that in cutting down some timber in Birkland and Bilhaugh, letters have been found cut or stamped in the body of the trees, denoting the king's reign in which they were thus marked. It seems that the bark was cut off and the letters cut in, after which the next year's wood grew over it, but without adhering where the bark had been cut. The cyphers are of James the First, of William and Mary; and one of King John! One of these, with James's cypher, was about one foot within the tree, and one foot from the centre; it was cut down in 1786. This tree must have been two feet in diameter, or two yards in circumference, when the mark was cut. A tree of this size is generally estimated at one hundred and

twenty year's growth, which number subtracted from the middle year of James's reign, would make 1492, the date of the planting of the tree. The tree with William and Mary had the mark about nine inches within the tree, and three feet three inches from the centre; cut down also in 1786. This mark of John was eighteen inches within the tree, and something more than a foot from the centre: it was cut down in 1791; but the middle year of John's reign was 1207, from which, if we subtract 120, the number of years requisite for a tree of two feet in diameter to arrive at that growth, it will make the date of its planting 1085, or about twenty years after the Conquest. The tree, therefore, when cut down in 1791, must have been 706 years old, a fact scarcely credible; for it appears from the trees whose marks are better authenticated, that those exactly of the same size, when marked, had increased twelve inches in diameter in 173 years, whilst this tree had increased no more than eighteen inches in 584 years. Major Rook says, that several with this mark had been cut down, so that deception or mistake is scarcely possible. This accurate delineator accounts for these phenomena, by supposing (as the increasing wood never adheres where the bark had been taken off), that the sap which rises from the roots through the capillary tubes of the wood, to the branches, returns in its circulation between the blea and the bark. " I have often (says he) examined many of the ancient hollow trees in Birkland and Bilhaugh, and always found that where the bark remained, even on their mutilated trunks, there they frequently put out small branches with leaves; but where that necessary covering of the returning sap was wanting, there was no appearance of vegetation."

OF INSTINCTS. (FROM DR. PALEY.)

An instinct is a propensity prior to experience, and independent of instruction. We contend, that it is by instinct that the sexes of animals seek each other; that animals cherish their offspring; that the young quadruped is directed to the teat of its dam; that birds build their nests and brood with so much patience upon their eggs; that insects, which do not sit upon their eggs, deposit them in those particular situations, in which the young,

when hatched, find their appropriate food; that it is instinct, which carries the salmon, and some other fish, out of the seas into rivers, for the purpose of shedding their spawn in fresh

water.

We may select out of this catalogue the incubation of eggs. I entertain no doubt, but that a couple of sparrows, hatched in an oven, and kept separate from the rest of their species, would proceed as other sparrows do, in every office which related to the production and preservation of their brood. Assuming this fact, the theory is inexplicable upon any other hypothesis, that of an instinct impressed upon the constitution of the animal. For, first, what should induce the female bird to prepare a nest before she lays her eggs? It is in vain to suppose her to be possessed of the faculty of reasoning; for no other reasoning will reach the case. The fulness or distension which she might feel in a particular part of the body, from the growth and solidity of the egg within her, could not possibly inform her, that she was about to produce something, which, when produced, was to be preserved and taken care of. Prior to experience, there was nothing to lead to this inference, or to this suspicion. The analogy was all against it; for, in every other instance, what issued from the body was cast out and rejected.

But, secondly, let us suppose the egg to be produced into day, how should birds know that their eggs contain their young? There is nothing either in the aspect, or the internal composition of an egg, which could lead even the most daring imagination to conjecture, that it was hereafter to turn out from under its shell a living perfect bird. The form of the egg bears not the rudiments of a resemblance of that of the bird. Inspecting its contents, we find still less reason, if possible, to look for the result which actually takes place. If we should go so far as, from the appearance of order and distinction in the disposition of the living substances which we noticed in the egg, to guess that it might be designed for the abode and nutriment of an animal (which would be a very bold hypothesis) we should expect a tadpole dabbling in the slime, much rather than a dry winged feathered creature; a compound of parts and properties impossible to be used in

a state of confinement in the egg, and bearing no conceivable relation, either in quality or material, to any thing observed in it. From the white of an egg, would any one look for the feather of a goldfinch? or expect, from a simple uniform mucilage, the most complicated of all machines, the most diversified of all collections of substances? Nor would the process of incubation, for some time at least, lead us to suspect the event? Who that saw red streaks shooting in the fine membrane which divides the white from the yolk, would suppose that these were about to become bones and limbs? Who, that espied two discoloured points first making their appearance in the cicatrix, would have had the courage to predict, that these points were to grow into the heart and head of a bird? It is difficult to strip the mind of its experience. It is difficult to resuscitate surprise, when famialiarity has once laid the sentiment asleep. But could we forget all that we know, and which our sparrows never knew, about oviparous generation; could we divest ourselves of every information, but what we derived from reasoning upon the appearances or quality discovered in the objects presented to us, I am convinced that harlequin coming out of an egg upon the stage, is not more astonishing to a child, than the hatching of a chicken, both would be, and ought to be, to a philosopher.

But admit the sparrow, by some means to know, that within that egg was concealed the principle of a future bird; from what chemist was she to learn, that warmth was necessary to bring it to maturity, or that the degree of warmth imparted by the temperance of her own body, was the degree required?

To suppose, therefore, that the female bird acts in this process from a sagacity and reason of her own, is to suppose her to arrive at conclusions which there are no premises to justify. If our sparrow, sitting upon her eggs, expects young sparrows to come out of them, she forms, I will venture to say, a wild and extravagant expecta tion, in opposition to present appearances, and to probability. She must have penetrated into the order of nature, further than any faculties of ours will carry us; and it hath been well observed, that this deep sagacity, if it be sagacity, subsists in conjunction with great stupidity, even in relation