influence more powerfully resists every other. Nevertheless, the lapse of ages, and especially the presence of man, has here introduced many modifications; for, in traversing the immense deserts of these high mountains, among the rare plants which form their herbage, some few of the commonest here and there occur. If the verdure takes a deeper tint than usual, contrasted with the gayer colour of the Alpine turf, the ruins of a hut, or a rock blackened by smoke, explain the mystery. Around these asylums of man, we find naturalized the common Mallow, Nettle, Chickweed, and common Dock. A shepherd had possibly sojourned here some weeks, and in driving his flocks here, had also attracted without knowing it, the birds, the insects, the seeds of the plants of his lowland cot. He may possibly never return, but these wild spots have received in an instant the indelible impression of his footsteps; so much weight has a being of his importance in the scale of nature. In other places, by destruction he has signalised his presence. Before he approached the mountains, the immense forests which covered their bases have fallen under his axe, for woods are not the abodes of man; he avoids the circuitous paths of so vast a labyrinth, suspecting danger under their, shades; he there mourns the absent sun, an object which every day renovates his delight; and therefore it is seldom that he penetrates a forest, without fire and sword in hand.

Accordingly the seeds of woodland plants become dormant in a soil now dried by the sun and wind, and no longer suitable to their germinating, Other vegetables take their places, the climate itself changing; for the temperature rises, the rains are less frequent, but more copious, the winds more inconstant and impetuous, deep gullies are formed in the sides of the acclivities by torrents, and rocks are deprived of the earth which covered them, and, at the same time, of the plants which ornamented them, by falls of immense loads of melting snow: thus the face of the

globe, where man inhabits, is more changed in one century, than in twenty where he is absent.

After all, in Alpine countries, the different soils, and their productions, retain most of their aboriginal character: there the primitive distribution of vegetables has been least disturbed; their localities can be easily traced, the influence of the air is most perceptible; there the contiguity of objects exhibiting more forcibly their similitudes and dissimilitudes, the eye of the observer takes in at one glance every trait, which is interesting; and if it is necessary for the geologist to visit these grand chains of mountains, to study the structure of the earth and those catastrophes, which have imprinted its present form, it is still more so for the horticulturist, who wishes to penetrate the mysteries of the primary dissemination of vegetables and their subsequent propagation, hoping thence to derive hints for their successful cultivation, and improvement, in the paradise surrounding his dwelling.

V. Description of a Bank for Alpine Plants, by Monsieur THOUIN, abridged from his Paper in the Annales du Musée, Vol. 6, page 183. By RICHARD ANTHONY SALISBURY, Esq. F. R. S. &c. Secretary.

Read April 2, 1811.

PLANTS from Alpine and frozen countries are cultivated in the Jardin des Plantes at Paris, on a Bank, sixty feet long, placed against the wall of a terrace, ten feet high, which faces the southeast so much, that the sun ceases to shine upon it between 10 and 11, A. M. This bank is divided into five steps, one foot wide, by nailing planks of oak, ten inches deep, to the top of as many rows of strong posts, charred at the bottom, and driven firmly into the ground; the taller posts are still further secured in their places by cross bars let into the wall.

Through the whole length of this bank runs a ditch, two feet deep, but sloping gradually towards the front up to nine inches in height, under the general level of the ground; and in making this ditch, its sides were plaistered six inches thick with mortar of brick mould and chopped straw, filling up all the cracks which appeared during the week it was left exposed to the air. After nailing the planks to the posts, the natural soil, which is of a light nature, was thrown into the hollow up to within about a foot of the surface of the slope, above which it was filled with sandy peat, such as Ling and Heaths grow in, passed through a screen. My reason for using all these precautions was to prevent the water necessary for the health of those Alpine plants in summer, running off too quickly into a bed of dry gravel underneath in a naturally moist soil, that expense and trouble may be saved.

APPENDIX.]

M. THOUIN'S Description of a Bank, &c. 25

I have sown on this bank the seeds received not only from the Alps, but several other frozen regions: for it is probable that the elevation of the atmosphere near the Poles corresponds with that of the highest mountains in France, rising gradually towards the equator; nor is this consideration so foreign to the business. of a gardener in naturalizing vegetables, as might be at first. supposed.

Roots of all the Alpine plants I could collect, have also been planted in this bank, and they thrive much better than when cultivated in pots on a stage, however open or airy, so that most of the following have greatly increased both by seeds and roots. Moehringia Muscosa, Viola Biflora, Androsace Carnea, and Lactea, Soldanella Alpina, Primula Farinosa,* Tussilago Alpina, Artemisia Glacialis, Salix Myrsinites, Retusa, and Reticulata.

The culture they require is, 1st, to keep the bank carefully weeded: 2dly, to reduce within bounds, many that grow and spread rapidly so as to exclude others: 3dly, to dig and lighten the surface frequently, that it may absorb air and water more readily: 4thly, to add three inches in depth of fresh sandy peat every year, in place of the old, which soon loses its humus, or nutritious part: 5thly, in giving the plants, at a certain season, not only daily, but hourly waterings; but this being one of the most important points, I shall enlarge more fully upon it.

Almost all Alpine plants are of humble stature, growing on steep declivities of rocks in a layer of humus, or vegetable earth, formed by the decomposition of Jungermannias, Lichens, and Mosses. The greater part of the year, they are covered with a bed of snow, which only begins to melt at stated periods of the day, after the rays of the sun have acquired great force. Then only do these Alpine plants awaken from torpidity, exhaling

* I have constantly found this plant growing wild in wet meadows that are seldom dry even in summer, at the foot of the mountains, and even in bogs. Secr.

quickly in this light black soil, the moisture which they have absorbed during the night: but the returning sun which excites them to action, also melts the snow above, the waters of which trickling down to their roots, give immediate refreshment. The sun, disappearing, these little vegetables are no longer exhausted, and a continuance of moisture would even be hurtful; accordingly the snow resuming its solid consistence with the cold of the night, this natural irrigation ceases, with a degree of exactness that the most careful gardener cannot perform.

From the above remarks, it will easily be deduced, that Alpine plants should have no water at all during winter and moist weather: on the contrary, that they should be kept perpetually moist during hot sunshine, by water dribbling through the soil to their roots, without wetting their leaves, which immediately evaporating by the heat, will cool the air just above them. In fact, it is only by a close imitation of the process of nature, that these vegetables of cold regions can be successfully cultivated in botanic gardens.

The last essential point relative to Alpine plants, is to cover them up on the approach of frost: this may appear a strange precaution to some, but when winter commences in their native soil, being immediately covered with snow to the depth of seven inches, they never feel a greater degree of cold than that of the freezing point, the soil itself being hardly frozen. The best covering is that of Fern, (Pteris Aquilina,) which does not absorb moisture so quickly, as most other sorts of haum.