humerous publications on the subject which are yearly issuing from the press, at the same time that they greatly advance the science, cannot fail to render it more diflicult of attainment to individuals. In the most favourable situations, and with all the advantages that can possibly be possessed, it is not easy to keep pace with its rapid progress, and to acquire a knowledge of the new matter which is continually accumulating from the separate labours of its admirers. Few botanists have the happiness to command a fortune adequate to the purchase of all the books that are professedly written on the subject. But besides these, many valuable dissertations are published in the Transactions of various scientific societies, which cannot be procured without purchasing a great num ber of others printed in the saine volume that are not immediately wanted, and yet add greatly to the expence. But if this difficulty be surmounted, another, and often insuperable obstacle still remains: a considerable proportion of them are written, not in the Latin or French languages, familiar to most naturalists; nor in Italian, which, though less common, is often understood; but in German, Swedish, Spanish, or Portuguese, which very few learned men have learnt, or have leisure to learn. The English botanist therefore is under great obligation to the translator of these tracts, who has given him easy access to treasures from which he was before entirely barred: they are ten in number.

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1. On the Organs of Perspiration of Plants, translated from the German of Hedwig. This able naturalist, who has deserved so well of the scientific world by his unwearied microscopic researches into the minutest parts of the vegetable creation, has in this concise tract directed his consummate skill to the examination of those pores in the leaves and other parts of 'plants, which he supposes were first seen by Von Gleichin, but which, as the translator informs us in a note, had before been detected by Saussure, and which are now gencrally supposed to be organs of perspiration. These pores he describes as single oblong apertures in the middle of numerous bodies, differently shaped in different plants, and communicating with

a set of ducts or vessels which he calls the

lymphatic vessels of the cuticle. He attributes to the pores a capacity of opening and shutting, but says nothing of their having a moveable valve, which is ex

pressly asserted by Willdenow in his prin ciples of botany. He observes that moisture as well as air may possibly be conveyed through these passages, but acknowledges that he is not sufficiently acquainted with the subject to give a decided opinion concerning it.

The translator has added to this tract some valuable obscrvations of Mr. Francis Bauer, and M. Decandolle, Mr. Bauer, who besides his distinguished excellence in botanic painting, is well skilled in microscopic investigation, has not been able to discover the supposed lymphatic ducts described by Saussure and Hedwig, and is of opinion that what they took for such are nothing more, than the edges or remaining parts of the dissepiments of the cells in the cuticle. M. Decandolle has found that there are such pores only on those parts of vegetables which are exposed to the influence of air and light; that fungi, lichens, hepaticæ, fui, and in general all plants or parts of plants which are constantly immersed in water, are totally destitute of them, and that sucendent plants which perspire but little have very

few.

2. Some Materials for the Illustration of the Botanical Geography of the Souilis western parts of Europe, translated from the German of Professor Link.

This tract relates to that department of the science which is called by Willdenow the history of plants, and modestly professes to be mere fragments and mate rials to assist in the future completion of the subject. It consists of four distinct lists, with some general deductions from them: 1. Of plants which are found in the greatest part of Europe from the 54th to the 35th degree of north latitude: 2. Of such as have two nearly allied species, one of which is found in northern, the other in southern climates, and which are never known to degenerate the one into the other: 3. Of those that belong to the Flora of Portugal, divided into the southern, the middle, and the northern, to which is annexed some brief observa tions on the Florus of Spain, south Germany, northern and middle France, and the south of England; and 4. Of plants frequent in north Europe, but not found in the south of Spain and Portugal.

These catalogues are confessedly very imperfect, and the conclusions drawn from them will consequently stand in need of being corrected, and differently modified, as the collection of well authen

ticated facts increases. The geography of botany has hitherto been little cultivated: but begins to gain greater attention, and promises to throw new light on many important parts of natural history. The only part of the world in which it has become a practical science, is, we believe, the United States of North America, where it has long been usual to judge of the nature, and to appreciate the value, of uncleaned land by the plants, and especially the trees, which it naturally produces. The most striking defect in the present essay arises from the deference which it pays to the artificial and accidental boundaries of the present independant sovereignties. Portugal has no natural separation from Spain. In the eye of the naturalist they form one country, of which he contemplates the grand features, the mountains, the valleys, and the plains, in connection with the elevation, the soil, the declination, and the particular exposure of the district where any plant is exclusively or most abundantly found. It is of no consequence to him where the line of political division cuts the banks of the Tagus and the Douro, and determines which village shall belong to the king of Portugal and which to the king of Spain. This may be fixed to-day and unfixed to-morrow, at the fiat of a Napoleon, or any other scourge of nations, of any other setter up and puller down of kings: but the everlasting hills will still remain fixed on their foundations, the majestic streams will still maintain their course, the great laws of nature, which determine the disposition of the mineral, the growth of the vegetable, and the enjoyment of the animal creation, will continue as they are settled by nature's God, in defiance of human power and human caprice.

3. On the Nature and Mode of Production of Agallochum or Aloes-wood, translated from the Portuguese of Loureiro.

This curious production has been imported from the East, and valued as a me dicine, and a grateful perfume, from the earliest ages of antiquity: but its natural history has been hitherto unknown. The author of the present tract had opportunities of seeing and examining it, and of learning the manner in which it is obtained, during a residence of many years in Cochin China, its native country. It is the produce of a tree which must be placed in decandria monogynia, and bejongs to the natural order of leguminosæ.

It is not, however, the wood of that tree in its natural state, which is white, without coloured veins, insipid and scentless; but is the immediate result of a disease analogous to the schirrous tumours of animal bodies, and arises from accidental and yet frequent obstructions in the trunk or branches, by which the alimentary juices are stopped in their passage, and their thick and oily part coagulated into a resi nous mass. This, when accumulated to a sufficient degree, extends and bursts the vessels and channels in which it was contained, and then presents a shapeless, hard, dark-coloured, fragrant, bitter substance, full of coarse veins, called agallochum. The manner in which it is gathered, the varieties to which it is subject in point of purity and strength, and some of the uses to which it is applied, are briefly detailed by the Portuguese mis sionary.

4. On the Genera of Orchidea, and their systematical Arrangement, translated from the Swedish of Professor Swarz.

5. Genera and Species of the Natura Order of the Orchidea: by Professor Swarz.

These two tracts taken together compose the largest and most valuable part of the collection. The natural order which they profess to illustrate is distinguished from all others by strongly marked characters, and contains a vast number of species. Professor Swarz has minutely examined more than two hundred; and the authors of the Flora Peruviana and Chilensis, assert that more than one thousand distinct ones may be found on the Cordilleras, within a very small tract of country. Great natural orders are always difficult to divide into genera. It cannot, the case with the orchidea. The structherefore, excite our surprize that this is ture of their parts of fructification is, moreover, so singular, and compared with all other plants, so anomalous, that authors could scarcely be expected to form precisely the same ideas concerning the ends they are severally designed to answer, and the names by which they should be called. The author of the present tracts, dissatisfied with the labours of his predecessors, which had indeed been limited to few species, offers a new, description and distribution into genera. In agreement with Jussieu he regards the corolla of Linnæus as the proper calyx, but differs from both nonsidering as a true corolla

man of Frederic Ehrhart.

This tract consists of short unconnected corrections of former authors, and does not admit of analysis or abridgment.

We have only to add, that these pieces have had the good fortune to fall into the hands of a translator who is well acquainted with the science, and as appears from several notes annexed to the text, has ready access to the best sources of infor mation.

THIS short pamphlet does not profess to afford much information that is absolutely new. Botanists, as the author observes, have long known that the blight in corn is occasioned by the growth of a minute parasitic fungus, which has escaped the notice not only of the mere practical farmer, but also of all professed writers on agriculture in the English language. The alarming state of the harvest in August 1804, naturally suggested to the president of the Royal Society, who is as eminent for the activity and disinterestedness of his public spirit, as for the extent and accuracy of his scientific attainments, that a popular address to his countrymen on the subject, accompanied by a plate from the admirable highly magnified drawings of Mr. Bauer, botanical painter to his majesty, might be the means of exciting general attention among those who are most interested in the event; and of obtaining, from intelligent agriculturists in all parts of the kingdom, the result of their own experience, founded on a course of well-directed observations. In this view he is entitled to the gratitude of every friend of mankind, even although it shall finally appear that the parasitic fungus is not the primary cause of the disease. It may indeed, we apprehend, be justly doubted, whether a living plant, in the full vigour of health, would permit the seed of the fungus to take root on its surface, and to penetrate into such parts of its substanice as are essentially connected with the vegetable economy. There seems to be inherent in all living organized matter, a power of self-preservation, which to a certain limit repels the approach or resists the operation of whatever would be in jurious to its welfare. The living animal stomach, for instance, is not acted upon by that gastric fluid which destroys the

texture of every dead animal or vegetable substance; but as soon as the principle of life is gone, becomes itself equally subject to its digestive power. In the same manner, young trees, and the young shoots of those that are old, possess a vigour which prohibits the growth not only of the parasitic fungi, which are universally known to be active agents in promoting and accelerating the process of putrefaction, but also of the musci, which do not appear to have the same destructive quality, or at least not in an equal degree. We look daily from the window of o elevated study (we hope our courteos readers will not call it a garret), upon a row of elm-trees which are peculiarly ble to be struck, as we conceive, by lig ning, in consequence of their being planted near a subterranean watercourse, and of the earth about some of their res being thereby kept in a state of constr moisture. Scarcely a summer passes la which some of their branches are pa blasted. The mischief they have sustained is soon made visible by the wither: 5 of their leaves: and in the course of Lit ensuing winter there is always upon the a plentiful crop of Tremella purpures, which completes what the lightning gan, and entirely deprives them of Ft, but gains no footing on the sound brand.. in their neighbourhood. We are therefore inclined to suspect that the seeds of the parasitic fungus which appears on bli_b ed corn, find in the early plant a preposing weakness which favours, or at lest does not repel their settlement and growth This weakness is probably occasioned of those cold easterly and northerly wink which in our climate are frequent in t spring about the time when the wintercon. is so far advanced, and has acquired sncl. 2 degree of succulence, as to be moet susap

tible of injury. It has commonly been observed by farmers, that plants which are what they call most rank, that is, luxuriant in their growth, are most frequently blighted. Their vessels are then most copiously supplied with sap, and are consequently most liable to be ruptured by any violent impulse.

It is also, we believe, generally found that the fields which are most exposed to these winds, are most generally infected. A very intelligent philosophical friend, who has had considerable experience in agriculture, has just now informed us, that in order to screen a field thus exposed, a very tall hawthorn-hedge was suffered to grow, which answered the purpose; but one year when there happened to be a gap in the fence, all the corn in the direction of the wind through the gap was blighted. There is also a field in our neighbourhood which is naturally of a good soil, and has long been kept in a state of high cultivation, but while it continued under the plough, was always subject to the same evil whenever it was sown with wheat. It slopes to the east, and fronts a small valley which operates as a kind of funnel to the wind, and increases its force. It may not be unimportant to add, that at a small distance to the east, and at right angles with the direction of the valley, there is a hedge which contains a considerable number of barberry-bushes; a circumstance which seems to favour the opinion so generally entertained by farmers, and rather favoured by the learned author of the present tract, that the neigh bourhood of this shrub has a pernicious influence on wheat.

But whatever opinion may be entertained concerning the original cause of the disease, the public are under great obligation to sir Joseph Banks, for the valuable hints which he has given on the subject, and for the measures which with his usual liberality he has employed to make them extensively known. His information with respect to the sufficiency of lean and shrivelled grain for all the purposes of seed-corn, is of peculiar importance and worthy of serious attention. We are sensible that the general practice of farmers is founded on a different opinion: and we acknowledge that we ourselves, who do not profess to have any practical knowledge of agriculture, were rather inclined to suspend our judgment; not thinking the growth of eighty grains of blighted wheat, sown in pots, and placed in a hothouse, a sufficiently decisive experiment to justify a tenant who wishes to pay his rent, in making a similar trial on a large scale, in the open air, and subject to the usual casualties of our variable climate. But the friend abovementioned has assured us that a few years since he himself made the experiment with complete success. In a field which had been uniformly manured, he sowed parallel divisions, or lands as they are called in his neighbourhood, one with the boldest and plumpest wheat he could procure, the next with such as was remarkably lean and shrivelled, and so on alternately through the whole field. The event exceeded his utmost hopes. The crop from the shrivelled grain was in no respect inferior to that obtained from the other.

THE first attempt in our language towards giving the common farmer somewhat of a scientific acquaintance with our indigenous grasses, was made by the late excellent Mr. Stillingfleet, in some ob servations annexed to his translation of a tract published in the Amoenitates Acadenicæ, under the title of Pan Suecicus. He drew up a catalogue of all that were hen known; distinguished them by Engish names, which have since, for the most art, been generally received; and partiularly recommended Anthoxanthum doratum, vernal grass; Alopecurus praensis, meadow fox-tail; Agrostis palus

tris (alba, Linn.) marsh bent; Agrostis capillaris, Hudson 1st. ed. but not of Linnæus, fine bent (A. vulgaris, Withering and Smith); Aira filexuosa, mountain hair-grass; Aira caryophyllea, silver hairgrass; Poa pratensis, angustifolia, and annua, great, narrow-leaved, and annual meadow-grasses; Festuca ovina, fluitans, and rubra, sheep's fote, and purple fescue; Avena flavescens, yellow oat-grass; Lolium perenne, perennial darnel-grass; and Cynosurus cristatus, crested dog's-tail grass. Mr. Curtis some time after pub lished his Observations, giving a fuller and more accurate catalogue, and particularly