for when the extractive juices, contained in the soil, have become exhausted, the oxygen of the atmosphere, by penetrating into the earth and abstracting from it a portion of its carbon, forms a new extract to replace the first. Hence we may account for a number of facts observed by the earlier phytologists, but not well explained. Du Hamel remarked that the lateral roots of plants are always the more vigorous, the nearer they are to the surface; but, it now appears, that they are the most vigorous at the surface, because they have then the easiest access to the oxygen of the atmosphere, or to the extract which it may form. It was observed, also by the same phytologist that perpendicular roots do not thrive so well, other circumstances being the same, in a stiff and wet soil, as in a friable and dry soil; while plants, with slender and divided roots, thrive equally well in both: but this is no doubt owing to the obstacles that present themselves to the passage of the oxygen in the former case, on account of the greater depth and smaller surface of the root. It was further observed, that roots which penetrate into dung, or into pipes conducting water, divide into immense numbers of fibres, and form what is called, the fox-tail root; but it is, because they cannot continue to vegetate, except by increasing their points of contact, with the small quantity of oxygen found in such mediums. Lastly, it was observed, that plants, whose roots are suddenly overflowed with water, remaining afterwards stagnant, suffer sooner than if the accident had happened by means of a continued current. It is, because, in the former case, the oxygen contained in the water is soon exhausted, while, in the latter, it is not exhausted at all. And hence, also, we may account for the phenomenon exhibited by plants vegetating in distilled water, under a receiver filled with atmospheric

air, which having no proper soil to supply the root with nourishment, effect the developement of their parts only at the expense of their own proper substance; the interior of the stem, or a portion of the root, or the lower leaves decaying, and giving up their extractive juices to the other parts.

Thus it appears that oxygen gas, or that constituent part of the atmospheric air, which has been found indispensable to the life of animals, is also indispensable to the life of vegetables. But although the presence and action of oxygen is absolutely necessary to the process of vegetation, plants do not thrive so well in an atmosphere of pure oxygen, as in an atmosphere of pure and common air. Whence it follows, that oxygen, though the principal agent in the process of vegetation, is not yet the only agent necessary to the health and growth of the plant; aud that the proportion of the constituent parts of the atmospheric air, is well adapted for the purposes both of vegetable and animal life.”

Polytechnic and Scientific Intelligence.
GREAT BRITAIN.

Society of Arts.

PUBLIC exhibitions are the order of the day. To this, however, we have no kind of objection, provided they tend to some beneficial purpose. The rooms of the Society of Arts, being inconvenient for the appropriate distribution, before a numerous audience, of the medals and premiums adjudged during the year, it was thought desirable to obtain the use of Drury-lane Theatre for the purpose. And on Wednesday, the 29th of May, the

Society, with his Royal Highness the Duke of Sussex at their head, proceeded, on the stage of the theatre, to distribute the various medals, &c. to the several successful candidates.

A great chair was placed behind a little table for the President, the Duke of Sussex; on seats on the stage sat the male and female dignitaries who were to witness the ceremonies on one side the female candidates sat on raised steps; and on the other the successful male aspirants for the honours of the Society. By noon the house was filled throughout-the coup d'oeil was charming.

Mr. Aikin addressed the audience in a sensible and intelligent discourse, which he elucidated in a manner that did honour to this respected individual. After which the delivery of the medals commenced.

In the class Agriculture, a representative of Messrs. Cowley and Staines' of Windsor, Bucks, received a large gold medal, and a gold Ceres medal, for drawing turnips in November, and preserving them in a sound state to April; and for the cultivation of the white poppy, whence they extracted 60lbs. of opium, equal to Turkey opium. Mr. Peart was rewarded for redeeming fifty-six acres of waste moor-land.

In the Polite Arts sixty-nine medals were awarded d; some to works of high promise; some to mere schoolpieces.

In Manufactures perhaps the most important improvement which was rewarded, was that on the silk ribbon loom, by Mr. J. Thomson, Jun. of Coventry.

A silver medal and twenty guineas were announced to Mrs. Wells of Connecticut, America, for a new material for plat in imitation of Leghorn. We once more call the Society's attention to the Bent growing so plentifully on

Edinburgh School of Arts.

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the sand hills on our shores, as an article every way likely to be beneficially manufactured into bonnets, &c. See 207 of our second volume.

In Chemistry only two rewards were bestowed; these were, one to Mr. H. W. Reveley, King-street, Bryanstone Square, for his communication respecting the nature and preparation of the stones used in Tuscany for grinding flour; the large silver medal.

The other to J. Meigh, Esq. Shelton, Staffordshire, for the discovery of a glaze, for vessels of common red earthenware, not prejudicial to the health of those who make use of them; the large gold medal.

The remainder of the proceedings we have it not in our power to report; the remaining classes of Mechanics, and Colonies, and Trade, must therefore be left for the Society's Transactions.

It appears that no facilities for being accurately informed were accorded to any of those powerful engines which lend their impetus to such escapements. This, as we have again and again repeated, is not judicious, nor at all worthy of the age, nor the Society.-The French savans know better how to arrange these things-how to make echoes, more powerful than the original sound, spread their doings over the world. But we have heretofore said enough on this subject. Associated bodies do not often improve by age.

Edinburgh School of Arts.

On the 24th of April, the first session of the School of Arts was closed. After Dr. Fyffe had finished his lecture, Mr. L. Horner, gave an account of the proceedings of the session. The success of this school has far surpassed the expectations of its friends and supporters.

Nearly 400 individuals, chiefly mechanics, have entered as students. The principal classes have been well attended; and among many who distinguished themselves by scientific exercises, may be mentioned three individuals from the blind asylum. Why have we not such a school or schools in the metropolis ?

Irish Academy.

THE artists of Ireland have been incorporated into a Society, similar to the Royal Academy in this country. A council of fourteen Academicians has been chosen, and ten Associates are to be elected next year from the exhibitors of Irish art,

Royal Society.

THE following papers have been read at this Society

since our last.

April 25. On the Mechanism of the Spine, by Mr. Earle. Observations on the Eclipse of August, 1821, by Mr. Dawes.

May 2. On the Nerves which associate the Muscles of the Chest in the actions of Breathing, Speaking and Expression, by Charles Bell, Esq.

A short account of some Appearances in the Moon, on the 24th of April, by Mr. Lawson.

May 9. Experiments and Observations on the Newry Pitch-stone, and on the artificial formation of Pumice, by the Right Hon. J. Knox.

May 16. On the Changes which the Egg undergoes during Incubation, by Sir E. Home, Bart.

May 23. On the Mathematical Laws of Electro-magnetism, by P. Barlow, Esq.

On the Height of Places in the Trigonometrical Survey; by B. Bevan, Esq.