oval, and having its extremities more and more pointed the nearer it approaches to the insertion of the branches and the leaves. When the leaves are alternate, the circle is less perfect, The extremities

become equally narrow, but alternately, and each on the side where the branch is to appear. When the leaves are spiral, the number of angles of the medullary case is equal to that of the leaves of which the spirals are composed. Thus the medullary case of the lime has four angles; that of the oak, the chesnut, the bramble, the pear-tree, almost all the fruit-trees, &c. has five angles, more or less regular, because the spirals succeed constantly in fives.

Grew and Bonnet alone seem to have been on the way of these ob servations. The first had observed very various forms in the medullary case, especially in that of the conical roots of culinary plants; but he did not observe the relation between these forms, and the dispositions of the branches and leaves. The second carefully examined vegetables with opposite, verticillated, alternate, and spiral leaves; but did not observe the connection of these dispositions with the form of the medullary case.

M. de Mirbel has continued his researches into the structure of the organs of fructification in vegetables, in which he has been seconded with a zeal and intelligence that he takes a pleasure in acknowledging," by M. Schubert, whom the Grand Duchy of Warsovia sent into France to complete his knowledge of botany, which he was afterwards to teach in Poland. These two botanists have examined all the genera of trees with needle-shaped leaves, or the coniferous, one of the most important to be known, on account of the singularity of its organization, of the greatness of the species which it includes, and of the uti lity of its products. Every body is able to distinguish, at the first glance of the eye, the cedar, the meleza, the spruce fir, the Scotch fir, the thuya, the cypress, the yew, the juniper; but though the botanists have studied with particular attention the organs of reproduction of these vegetables, they are not agreed about the characters of the female flower; or to speak more correctly, the greater number are of opinion that the stigmata of the spruce fir, the Scotch fir, the cedar, and the meleza, have not yet been observed. In this respect, therefore, these trees are in reality cryptogamous. MM. Mirbel and Schubert go farther they affirm that the female flower of the yew, the juniper, the thuya, the cypress, &c. is not better known; and that all the genera of coniferous plants have a common character, which has hitherto misled observers, and which consists in the existence of a cup, not similar to that in the flower of the oak, but more deep, concealing entirely the ovarium, and contracted like the neck of a bottle at its orifice. The female flower enclosed in this case has escaped observation. In the thuya, yew, juniper, cypress, &c. the cup is strait; and by an error, occasioned by the extreme smallness of the organs, the orifice of this cup has been always mistaken for the stigma. In the cedar, meleza, spruce fir, and Scotch fir, the cup is reversed, and its orifice is very difficult to perceive. It is only within these few years that it has been observed in England by Mr. Salisbury, and in France by MM. Poiteau, Mirbel, and Schubert. These botanists

have not hesitated to consider it as the stigma; and this was natural, because it had been agreed upon that the stigma of the yew, the thuya, the cypress, &c. was placed at the orifice of the cup: but farther researches have undeceived MM. Mirbel and Schubert. By a delicate dissection, they have ascertained that what is generally taken for the female flower in coniferous plants is only the cup, the form of which resembles that of a pistil, and that it contains in its cavity the true flower, which is provided with a membranous calix, adhering to the ovarium, and with a stigma, sessile in all the genera except the ephedra.

It must be obvious that this structure, so different from what had hitherto been imagined, will occasion great changes in the explanation of the characters, of the family, and of the genera.

According to Mirbel, the female flower of the plants of the family of cycas has an organization analogous to that of coniferous plants. This supports the opinion of M. Richard, who places these two families together among dicotyledonous plants; but M. Mirbe! is of opinion, that as long as the characters of vegetation serve for the base of the two great divisions of plants with visible flowers, the cycadea cannot be separated from the palms.

The organization of the male flower of mosses has likewise engaged the attention of Mirbel and Schubert. After Hedwig, it would have been difficult to discover any thing new on this subject; but the bursting of the anthers, and the emission of the pollen, were phenomena doubted of by several botanists. Our two botanists declare that they have seen the most unequivocal proofs of the existence of these phenomena. The organs which Hedwig calls male in the Polytrichum commune, placed upon water, split at the summit, and threw out an oleaginous liquid, which extended itself like a thin cloud on the surface of the water. Mirbel and Schubert then subjected to comparative observation the pollen of a great number of phenerogamous plants, and ascertained that they exhibited the same phenomena as the male organs of mosses. This induces them to think that the parts called anthers by Hedwig may be nothing else than simple grains of pollen of a particular shape.

He has

M. Mirbel has continued his researches on germination. observed, contrary to the generally-received opinion, that the radicle does not always make its appearance first. In many cyperaceous plants it is always the plumula which appears first. The same botanist has republished, with important modifications and additions, his opinions respecting the organization of stems, respecting their growth, and respecting the structure, both internal and external, of the organs of fecundation of plants,

M. Henri de Cassini, son of one of our associates, a name so cele brated in astronomy, has presented to the Class a memoir, which augurs success in a different science. He has examined with peculiar care the style and stigma in the whole family of plants known by the name of compound, syngenesious, or symantherous; and these small organs have exhibited a number of curious differences, which have induced him to propose a division of these plants, founded solely on the modi3 fications

fications of these two parts of the pistil. We regret that we cannot follow the skilful observer in the details into which he has gone, and which he has described and drawn with remarkable neatness. It cannot be doubted but they will one day be of great service in perfecting the classification of this family, so numerous and so natural; the subdivision of which, in consequence, ought to be more difficult than of any other.

There are few families of vegetables so directly useful to man as the grasses, which comprehend wheat, rye, rice, mais, sorgho, sugarcane, barley, oats, millet, &c. To name these plants is enough to show the importance of a work which would enable us to distinguish them with certainty. The characters hitherto employed are generally regarded as insufficient. At each step the observer finds himself stopped. It is difficult, indeed often impossible, to find the true genus of the plant which he examines. Frequently the characters adopted only apply to a few species, and do not occur in the rest of the genus. M. Palisot de Beauvois has undertaken a general examination of this family, which he has published under the name of Essai d' Agrostographie. He has endeavoured to put an end to all this confusion, and to give to each genus constant characters, easy to perceive, so that the observer can never be at a loss.

For this purpose he has been obliged to adopt new bases, which he has already announced in his Flora of Oware and Benin. These depend principally on the separation or union of the sexes, on the composition of the flower, and on the number of its envelopes. Twenty-five plates, in which all these characters are represented, facilitate the study of these plants, which interest all the orders of society, even those persons who do not make botany a peculiar study.

M. de Beauvois continues his Flore d' Oware et de Benin, the thirteenth number of which is published; and his History of Insects collected in Africa and America, the eighth number of which has appeared.

M. de la Billardiere has finished his collection of the rare plants of Syria and Libanus, by the fourth and fifth parts, The same naturalist has communicated to the Class peculiar and interesting observations in natural history, which he made during his voyage in the Levant, the publication of which has been interrupted by the longer and more dangerous voyage which he made in the Entrecasteaux, an account of which was given to the public several years ago.

M. Gouan, correspondent of the Class at Montpellier, has published a description of the generic characters of the ginko biloba, a singular tree of Japan, which has been long known in Europe, but which, never having blossomed, could not be properly classified in the system.

There is a family of plants much less important than the grasses in point of utility, but much more singular in their characters, and which can only be seen vegetating on the sea-shore, namely, the fuci, and marine plants analogous to them. M. Lamouroux, professor of natural history at Caen, placed favorably in a city so near the coast,

has

has made these plants a particular object of study. He gives them the common name of thalassio-phytes, and divides them into various tribes, the characters of which he has been obliged to take in all parts of the plant, because he could not find sufficient characters in the organs of fructification, which usually serve as a basis to these divisions.

Calculus from the Urethra of a Hog.-Dr. Thomson, in his Annals of Philosophy for July, mentions that he received some time ago from Mr. Colville, surgeon in Ayton, Berwickshire, a calculus extracted from the urethra of a hog. It is nearly spherical; weighs 44.2 grains; its specific gravity is 1.595; it is white; has a silky lustre; and is composed of a congeries of very small crystals, which, as far as can be judged by the eye, consist of flat four-sided prisms. The calculus is soft, so that the crystals are very easily separated from each other. This calculus is composed entirely of phosphate of lime. When heated with potash, no smell of animonia can be perceived, The crystals dissolve without effervescence in muriatic acid, and are precipitated in the state of a white powder by pure ammonia.

Hydrosulphurets.-Thenard has lately published some observations on the hydrosulphurets, which deserve the attention of chemists.

1. When a saturated hydrosulphuret is heated along with sulphur, a portion of the sulphur is dissolved, and a quantity of sulphureted hydrogen gas escapes. If there be an excess of alkali, the sulphur is dissolved as usual, but little or no sulphureted hydrogen escapes. Hence we see that the hydrogureted sulphurets contain less sulphureted hydrogen than the hydrosulphurets.

2. When the saturated hydrosulphurets are raised to the boiling point, a portion of sulphureted hydrogen always makes its escape. By this method the hydrosulphuret of magnesia may be decomposed altogether, and hydrosulphuret of lime nearly so. Hydrosulphuret of potash and soda become very alkaline.

3. Hydrosulphuret of ammonia may be obtained in crystals by surrounding with ice a flagon containing a mixture of sulphureted hydrogen and ammoniacal gases. It crystallizes in needles, and is white; but becomes speedily yellow when exposed to the air. It is very volatile, rising spontaneously to the top of the phial in which it is kept. By this means it may be separated from the hydrogureted sulphuret of ammonia.

4. When ammoniacal gas and sulphur are passed together through a red-hot porcelain tube, hydrogen gas and azotic gas are disengaged, and a great quantity of hydrogureted sulphuret of ammonia crystallized, When this substance is put into a phial, pure crystals of hydrosulphuret of ammonia gradually sublime from it.

5. The fuming liquor of Boyle smokes in oxygen gas or common air; but not in azotic gas or hydrogen gas. Hence the smoking must be owing to the presence of oxygen. Thenard supposes that it acts. by converting the liquor into hydrogureted sulphuret, or into sulphite.-Ann. de Chim. Ixxxiii. 132.

Το

To Medical Practitioners in every Part of the United Kingdom. The Board of the National Vaccine Establishment have remarked, with great concern, that the mortality from the Small-pox has, this year, increased considerably. This effect they have reason to attribute to the inconsiderate manner in which great numbers of persons are still, every year, inoculated for the Small-pox, at public charities and private houses; and are, afterwards, required to attend two or three times a-week, at the places of inoculation, through every stage of the disease. The contagion, by these means, is propagated in an extensive manner, and to an alarming degree. The same observation has been made in Ireland. The Royal College of Surgeons of Dublin, in a late communication to the National Vaccine Establishment, observe, that "for several years, the Members and Licentiates of the College, and, it is believed, all regular Physicians and Apothecaries in Ireland, have adopted the practice of Vaccination, their confidence in the anti-variolous effects of which remains unshaken; but it has been ascertained, that some unauthorised practitioners continue to inoculate for the Small-pox, and thus renovate and support sources of contagion." To obviate this mischief, the National Vaccine Establishment most earnestly recommend to the several branches of the faculty, in every part of the kingdom, after the example of the most eminent members of the profession, both in London and Dublin, to discourage inoculation for the Small-pox, by an agreement among themselves to decline the use of variolous matter.* The Association of the Medical Gentlemen of Glocestershire, a copy of which is subjoined, is a model of good conduct, which, if imitated in all other parts of the kingdom, would soon open to us the pleasing prospect of the speedy extinction of a disease, which has, for centuries, been no less detrimental to the population of states, than prejudicial to the health of mankind. FR, MILMAN, President.

By Order of the Board, JAMES HERVEY, Reg. Resolutions of the Medical Practitioners in the County of Glocester. Resolved,-I. That we see, with regret, the prejudices hostile to Vaccination, which exist in this neighbourhood.

II. That the honor of our profession, and the reputation of this county, require that every possible means should be employed to dispel them.

III. That those gentlemen who are satisfied of the efficacy of Vaccination, be requested to unite with us in forming a Society, to be called "The Glocestershire Vaccine Association."

IV. That the objects of this Association shall be, to promote Cow pox, and discourage Small-pox Inoculation.

V. That, with this intention, the members of this Association shall individually and collectively declare, that they, considering their knowledge of Cow-pox, do not believe themselves entitled either to

* We refer the reader to the Resolutions of the Royal Colleges of Surgeons of London and Dublin, published in the Report of the Board for 1812, in which their determination not to inoculate with variolous matter, is recorded.

practice,