forbidding rudeness of her manners. The first publication of madame de Stael, was a vindication of the character and writings of Rosseau, in 1789, but prior to this, she had written three short novels, which were printed at Lausanne, in 1795. At the beginning of the French revolution, this lady took a more active part in the convulsions which overturned the monarchy, than became either her sex or her situation as the wife of a foreign ambassador. She involved herself indeed so much in those scenes, as to become an object of public attention; and in 1793, she found it necessary to seek an asylum in England; but, two years afterwards, her husband being appointed ambassador to the French republic, she had the privilege of returning to Paris; and about this time she endeavoured to conciliate the men in power by publishing her "Thoughts on Peace addressed to Mr. Pitt," a pamphlet filled with sophistry, though it received the praises of Mr. Fox. About this time she lost her mother, and in 1798, her husband, neither of which events could repress her literary ardour or restrain her from publishing, for at this period she wrote a play called "Secret Sentiment," and a work, "On the Influence of Literature upon Society." In 1800, when Buonaparte passed through Switzerland, he visited Madame de Stael, who talked to him a great deal about her plans for the organization of France, on which the first consul very sarcastically replied: "Who educates your children, madame?" During her residence in Switzerland she wrote her novel of "Delphine," the elegance of which will hardly be admitted as an excuse for its tendency. Shortly after this she accompanied her father to Paris, but her residence there was short, for the freedom of her opinions and the popularity of Necker, induced Buonaparte to pronounce a sentence of banishment against madame de Stael, who said to him, "You are giving me a cruel celebrity; I shall occupy a line in your history." This, perhaps, might be wit, but it was far from being prudent; and she felt the effects of her indiscretion, for having settled near Rouen she was ordered to remove to a greater distance from Paris, on which she withdrew to Frankfort, with her

VOL. X.

friend and protector Benjamin Constant. From Frankfort madame de Stael went to Berlin, where she received the intelligence of her father's illness, on which she hastened to Weimar, but found that he had died before her arrival, April 9, 1804. As soon as the first emotions of grief subsided, she employed herself in arranging his papers for publication, and they accordingly appeared in print the same year, at Geneva. In this publication, she was mean enough to pay a high-flown compliment to Buonaparte, in hopes, no doubt, of softening down his resentment, though the man himself, and every body else, well knew that the panegyric did not proceed from the heart. The sentence of her banishment remained, and to alleviate her uneasiness under the decree, she travelled to Italy, which produced another novel full as extravagant and beautiful as Delphine. She afterwards resided, for some time, at the Swedish capital, where she formed a close intimacy with the crown prince, Bernadotte, to whom she dedicated, in a very flattering style, her little work on Suicide. From Stockholm, madame de Stael passed over to England, where she remained while the allies were marching upon Paris, to which city she returned on the restoration of Louis XVIII, in 1814.

PROPERTIES OF PLANTS.

From the Literary Panorama. The following extracts from a lecture on Agricultural Chemistry, by sir Humphrey Davy, are particularly worthy the attention of the ingenious. They open a view of the operations of Nature on a large scale, that is at once striking and instructive. The vegetable kingdom is distributed in great masses all over the face of the earth; and it produces effects accordingly. The numbers of the animal kingdom bear but a small proportion to it, considered as to such effects. Without entering into particulars, we shall set before our readers the general results of this learned lecturer's disquisitions. Sir Humphrey had been observing, that, when the leaves of vegetables perform their healthy functions, they tend to purify the atmosphere in the common variations of weather, and changes from light to darkness. Vege32

tables, he thinks, produce more oxygen than they consume: animals, on the contrary, are constantly consuming this gas. If every plant, during the progress of its life, makes a very small addition of oxygen to the air, and occasions a very small consumption of carbonic acid, the effect may be conceived adequate to the wants of nature.

'It may occur as an objection, that if the leaves of plants purify the atmosphere, towards the end of autumn, and through the winter, and early spring, the air in our climates must become impure, the oxygen in it diminish, and the carbonic acid gas increase, which is not the case: but there is a very satisfactory answer to this objection. The different parts of the atmosphere are constantly mixed together by winds, which, when they are strong, move at the rate of from 60 to 100 miles in an hour. In our winter, the south-west gales convey air, which has been purified by the vast forests and savannas of South America, and which, passing over the ocean, arrives in an uncontaminated state. The storms and tempests which often occur at the beginning, and towards the middle of our winter, and which generally blow from the same quarter of the globe, have a salutary influence. By constant agitation and motion, the equilibrium of the constituent parts of the atmosphere is preserved; it is fitted for the purposes of life; and those events, which the superstitious formerly referred to the wrath of heaven, or the agency of evil spirits, and in which they saw only disorder and confusion, are demonstrated by science, to be ministrations of divine intelligence, and connected with the order and harmony of our system. . . .

The experiments of Montgolfier, the celebrated inventor of the balloon, have shown that water may be raised almost to an indefinite height by a very small force, provided its pressure be taken off by continued divisions in the column of fluid. This principle, there is great reason to suppose, must operate in assisting the ascent of the sap in the cells and vessels of plants which have no rectilineal communication, and which every where oppose obstacles to the perpendicular pressure of the sap. The changes taking place in the leaves and buds, and the degree of their power of transpiration, must be intimately connected like

wise with the motion of the sap upwards. This is shown by several experiments of Dr. Hales.

'A branch from an apple tree was separated and introduced into water, and connected with a mercurialgage. When the leaves were upon it, it raised the mercury by the force of the ascending juices to four inches; but a similar branch, from which the leaves were removed, scarcely raised it a quarter of an inch.

"Those trees, likewise, whose leaves are soft and of a spongy texture, and porous at their upper surfaces, displayed by far the greatest powers with regard to the elevation of the sap.

'The same philosopher, found that the pear, the quince, cherry, walnut, peach, gooseberry, water-elder, and sycamore, which have all soft and unvarnished leaves, raised the mercury under favourable circumstances from three to six inches. Whereas the elm, oak, chesnut, hazel, sallow, and ash, which have firmer and more glossy leaves, raised the mercury only from one to two inches. And the evergreens, and trees bearing varnished leaves, scarcely at all affected it; particularly the laurel and the lauristinus. .

'As the operation of the different physical agents, upon the sap vessels of plants ceases, and the fluid becomes quiescent, the materials dissolved in it by heat, are deposited upon the sides of the tubes now considerably diminished in their diameter; and in consequence of this deposition, a nutritive matter is provided for the first wants of the plant in early spring, to assist the opening of the buds, and their expansion, when the motion from the want of leaves is as yet feeble.

"This beautiful principle in the vegetable economy was first pointed out by Dr. Darwin: and Mr. Knight has given a number of experimental elucidations of it.

"The joints of the perennial grasses contain more saccharine and mucilaginous matter in winter than at any other season; and this is the reason why the Fiorin or Agrostis alba, which abounds in these joints, affords so useful a winter food.

'The roots of shrubs contain the largest quantity of nourishing matter in the depth of winter; and the bulb in all

plants possessing it, is the receptacle in which nourishment is hoarded up during the winter.

• In annual plants the sap seems to be fully exhausted of all its nutritive matter by the production of flowers and seeds; and no system exists by which it can be preserved...

In perennial trees a new alburnum, and consequently a new system of vessels is annually produced, and the nutriment for the next year deposited in them: so that the new buds, like the plume of the seed, are supplied with a reservoir of matter essential to their first development.

The old alburnum is gradually converted into heart-wood, and being constantly pressed upon the expansive force of the new fibres, becomes harderdenser, and at length loses altogether its vascular structure; and in a certain time obeys the common laws of dead matter, decays, decomposes, and is converted into aëriform and carbonic elements; into those principles from which it was originally formed.

The decay of the heart-wood seems to constitute the great limit to the age and size of trees. And in young branches from old trees, it is much more liable to decompose than in similar branches from seedlings. This is likewise the case with grafts. The graft is only nourished by the sap of the tree to which it is transferred: its properties are not changed by it: the leaves, blossoms, and fruits, are of the same kind as if it had vegetated upon its parent stock. The only advantage to be gained in this way, is the affording to a graft from an old tree a more plentiful and healthy food than it could have procured in its natural state; it is rendered for a time more vigorous, and produces fairer blossoms and richer fruits. But it partakes not merely of the obvious properties, but likewise of the infirmities and dispositions to old age and decay, of the tree whence it sprung.

"It is from this cause that so many of the apples, formerly celebrated for their taste and their uses in the manufacture of cider, are gradually deteriorating, and many will soon disappear. The golden pippin, the red streak, and the moil, so excellent in the beginning of the last century, are now in the extremest stage of their decay; and, how

ever carefully they are ingrafted, they merely tend to multiply a sickly and exhausted variety.

'The trees possessing the firmest and the least porous heart-wood, are the longest in duration.

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Amongst our own trees, the chesnut and the oak are pre-eminent as to durability; and the chesnut affords rather more carbonaceous matter than the oak. 'In old Gothic buildings these woods have been sometimes mistaken one for the other: but they may be easily known by this circumstance, that the pores in the alburnum of the oak are much larger and more thickly set, and are easily distinguished; whilst the pores in the chesnut require glasses to be seen distinctly.

'In consequence of the slow decay the heart-wood of the oak and chesnut, these trees, under favourable circumstances, attain an age which cannot be much short of one thousand years.

The beech, the ash, and the sycamore, most likely never live half so long. The duration of the apple tree is not, probably, much more than 200 years: but the pear-tree, according to Mr. Knight, lives through double this period; most of our best apples have been introduced into Britain by a fruiterer of Henry the Eighth, and they are now in a state of old age.

'The decay of the best varieties of fruit-bearing trees which have been distributed through the country by grafts, is a circumstance of great importance. There is no mode of preserving them; and no resource, except that of raising new varieties by seeds.

'Where a species has been ameliorated by culture, the seeds it affords, other circumstances being similar, produce more vigorous and perfect plants; and in this way the great improvements in the productions of our fields and gardens seem to have been occasioned.

'Wheat in its indigenous state, as a natural production of the soil, appears to have been a very small grass: and the case is still more remarkable with the apple and the plum. The crab seems to have been the parent of all our apples. And two fruits can scarcely be conceived more different in colour, size, and appearance, than the wild plum and the rich magnum bonum.

The seeds of plants, exalted by cul

tivation, always furnish large and improved varieties; but the flavour, and even the colour of the fruit seems to be a matter of accident. Thus, a hundred seeds of the golden pippin will all produce fine large-leaved appletrees, bearing fruit of a considerable size; but the tastes and colours of the apples from each will be different, and none will be the same in kind as those of the pippin itself. Some will be sweet, some sour, some bitter, some mawkish, some aromatic; some yellow, some green, some red; and some streaked. All the apples will, however, be much more perfect than those from the seeds of a crab, which produce trees all of the same kind, and all bearing sour and diminutive fruit.

The power of the horticulturist extends only to the multiplying excellent varieties by grafting. They cannot be rendered permanent; and the good fruits at present in our gardens, are the produce of a few seedlings, selected probably from hundreds of thousands; the results of great labour and industry, and multiplied experiments.

The larger and thicker the leaves of a seedling, and the more expanded its blossoms, the more it is likely to produce a good variety of fruit. Short leaved trees should never be selected; for these approach nearer to the original standard: whereas the other qualities indicate the influence of cultivation.

'In the general selection of seeds, it would appear that those arising from the most highly cultivated varieties of plants, are such as give the most vigorous produce; but it is necessary from time to time to change, and as it were, to cross the breed.

'By applying the pollen, or dust of the stamina, from one variety to the pistil of another of the same species, a new variety may be easily produced; and Mr. Knight's experiments seem to warrant the idea, that great advantages , may be derived from this method of propagation.

'Mr. Knight's large peas, produced by crossing two varieties, are celebrated amongst horticulturists, and will, I hope, soon be cultivated by farmers.

'I have seen several of his crossed apples, which promise to rival the best of those which are gradually dying away in the cider countries.

And his experiments on the crossing of wheat, which is very easily effected, merely by sowing the different kinds together, lead to a result which is of considerable importance. He says, in the Philosophical Transactions for 1799, "in the years 1795 and 1797, when almost the whole crop of corn in the island was blighted, the varieties obtained by crossing alone escaped, though sown in several soils, and in very different situations."

By making trees espaliers, the force of gravity is particularly directed towards the lateral parts of the branches, and more sap determined towards the fruit-buds; and hence they are more likely to bear when in a horizontal than when in a vertical position.

"The twisting of a wire, or tying a thread round a branch has been often recommended as a means of making it produce fruit. In this case the descent of the sap in the bark must be impeded above the ligature; and more nutritive matter consequently retained and applied to the expanding parts.

"In engrafting, the vessels of the bark of the stock and the graft cannot so perfectly come in contact as the alburnous vessels, which are much more numerous, and equally distributed; hence the circulation downwards is probably impeded, and the tendency of the graft to evolve its fruit-bearing buds increased.

'By lopping trees, more nourishment is supplied to the remaining parts; for the sap flows laterally as well as perpendicularly. The same reasons will apply to explain the increase of the size of fruits by diminishing the number up

on a tree.

'As plants are capable of amelioration by peculiar methods of cultivation, and of having the natural term of their duration extended; so, in conformity to the general law of change, they are rendered unhealthy by being exposed to peculiar unfavourable circumstances, and liable to premature old age and decay.'

LOCUSTS.

To the Editor of the Lit. Panorama.

Observing in your Panorama No. 26, for Nov. 1816, some account of the locusts of North America, I take the liberty of writing you some additional no

tices on that subject, which seems to be a branch of entomology but little known.

In the month of June, 1798, as I was crossing the state of Pennsylvania on foot, having passed several of the ridges of mountains called properly the Apalachian mountains, my attention was attracted by an unusual hum, or buzz in the air; and looking up I saw several large insects on the wing; they were brown, and flew heavily; about an inch in length, and having four guaze-like wings. Their note there is no describing-it was rather long, and somewhat piercing-having a slight inflection of tone, as if divided into two syllables, which (together with the religious leaning of the people) produces the notion that they say "PHARAOH." While I was but entering on the confines of the tract of land which they then covered, I could distinguish the beginning and end of the note of each insect I saw; but in a short space (a few miles) they were so numerous as to excite great attention; though I still had formed no distinct idea what they were. In two days journey afterwards, arriving at Pittsburgh (at the head of the Ohio) I found the people all talking of nothing else but the locusts, which indeed was no wonder, for they were so numerous that the hum continued without intermission the whole day, and by dint of numbers was disagreeably loud and importunate.—I did not then stay long in Pittsburgh, but pursued my expedition down the Ohio to Kentucky, and returned in about a month through the Ohio states (unsettled territory) to Pittsburgh again: the noise was far from being over; but I began to observe a phenomenon on the trees which I could not account for. Every tree whether in the woods, or in the gardens, in the town or out of it, was hung with dead twigs, having their leaves on, but dried and turned of various colours like autumn. Iinquired of the people the reason of this appearance, and found that it was occasioned by the locusts. I was now anxious to examine the process of their ravages, and I found that twigs of the last year's shoot were perforated to the pith, by holes in rows placed as near together as the teeth in a fine ivory comb (and of course as small) and as many as could be bored between the

knots of the twig, in two or three places on each. On large trees some hundreds of twigs were so perforated, and in every hole was deposited an egg, or embryo of a maggot.-Owing to the heat of the summer, the twigs so injured were killed, and twisting with the process of drying away, they hung as I have described, giving the woods a most singular and unnatural appearance.

It may seem astonishing in the economy of nature as to the re-production of these creatures, but the larvæ in every twig that dies, dies also; nor could I find living maggots in any shrub or tree but only in the twigs of the sasafras; these twigs being more tenacious of life, sustained the puncturing, without yielding to the drought;—I cut off many of them, and sliding a small knife along the punctures, deeper than the bark, cut through a row of small white maggots, which gave out a milky moisture. At the latter end of the year the locusts disappeared, and no one considered how, or what got them. They might perhaps, occupy a tract of land about 100 miles square.

In the year 1800 I was at Baltimore, and walking in Howard's park (in the beginning of June) at the back of that city, I observed innumerable holes under the trees (like the holes out of which our black beatles arise in spring,) and looking into the trees I perceived the under sides of their leaves filled with wingless insects which adhered to them; every leaf that I could distinctly see had three or four on it. In a few days the whole atmosphere was alive with locusts, and the hum was loud and unceasing; the exuvia dropped speedily from the leaves, and lay under the trees in such quantities that bushels might soon have been gathered. I now perceived that the creatures made their way out of the earth, without wings, and crept up the trees, fastening themselves underneath the leaves, where in a short time they were perfected; a suture then opened down the back, and the winged insect dropped out (certainly upon its wings,) being thenceforth a tenant of the air. This was the second flight that I had the opportunity of observingbut at a considerable distance from the first, and I had no means of ascertaining how far they extended. Neither can I specify the period of their return