rendering its emanations more considerable. Sound was also a conductor of magnetism; and in order to communicate the fluid to the piano forte, nothing more was necessary than to approach to it the iron rod. The person who played upon the instrument, furnished also a portion of the fluid; and the magnetism was transmitted by the sounds to the surrounding patients. The cord which was passed round the bodies of the patients was destined, as well as the union of their fingers, to augment the effects by communication. The interior part of the bucket was so constructed as to concentre the magnetism; and was a grand reservoir, from which the fluid was diffused through the branches of iron that were inserted in its lid. The patients then, arranged in considerable number, and in successive ranks, round the bucket, derived the magnetic virtue at once from all these conveyances:from the branches of iron, which transmitted to them that of the bucket;-from the cord which was passed round their bodies, and the union of their fingers, which communicated to them that of their neighbours;-and from the sound of the piano forte or a musical voice, which communicated through the air.

tients were besides magnetised directly, by means of a finger or a bar of iron, guided before the face, above or behind the head, and over the surface of the parts affected, the distinction of the poles still observed. They were also acted upon by a look, and by having their attention excited. But especially they were magnetised by the application of the hands, and by the pressure of the fingers upon the hypochonders and the regions of the lower belly; an application frequently continued for a long time, sometimes for several hours.

In this situation the patients offered a spectacle extremely varied, in proportion to their different habits of body. Some of them were calm, tranquil, and unconscious to any sensation; others coughed, spat, were affected with a slight degree of pain, a partial or an universal burning and perspiration; a third class were agitated and tormented with convulsions. These convulsions were rendered extraordinary by their frequency, their violence, and their duration. As soon as one person was convulsed, others presently were affected by that symptom. Accesses of this kind sometimes lasted upwards of three hours; they were accompanied with expectorations of a thick and viscous water, brought away by the violence of the efforts. Sometimes these expectorations were accompanied with small quantities of blood; and there was among others a lad who frequently brought up blood in considerable abundance. These convulsions were characterised by precipitate and involuntary motions of all the limbs, or of the whole body; by a contraction of the throat; by sudden affections of the hypochonders and the epigastrium; by a distraction and wildness in the eyes; by shrieks, tears, hiccupings, and immoderate laughter. They were either preceded or followed by a state of languor and reverie, by a species of dejection, and even drowsiness. The least unforeseen noise occasioned starting; and it was ob

served, that the changing the key and the time in the airs played upon the piano forte, had an effect upon the patients; so that a quicker motion agitated them more, and renewed the vivacity of their convulsions. Nothing could be more astonishing than the sight of these spasms. One that had not seen them could have no idea of them; and in beholding the whole scene, the profound repose of one class of patients was not less striking than the violence with which another class was agitated.

The first part of the work to which I have alluded, by Thouret, had for its object to show, that the theory of Mesmer, instead of being a novelty in science, was an ancient system, which had been abandoned by the learned a century before. He demonstrated, in the most satisfactory manner, by precise references to the writings of Paracelsus, Van Helmont, Godenius, Bargravius, Libavius, Wirdig, Maxwel, Sir Kenelm Digby, Santanelli, Tentzel, Kircher, and Borel, that all the propositions published and avowed by Mesmer, were positively laid down by one or other of these authors. In the second part, Thouret proves, by observations and reasoning, remarkable for their acuteness and good sense, that all the effects ascribed by Mesmer to the operation of a new species of magnetism, were to be attributed solely to the influence of the imagination on the body; that they admitted of the same explanation as the cures of the two famous empirics, Greatrakes and Gassner; and that to pretend to the discovery of a curative means, which should extend to every species of disease, or, in other words, to a universal medicine, was an illusion unworthy of an enlightened age.

This work of Thouret's received, from a committee of the Royal Society of Medicine appointed to examine it, that praise to which it was so justly entitled, from the talent and the erudition it displayed; and it cannot be doubted, that its influence would alone have been sufficient to have arrested the progress of the doctrine it exposed, even if animal magnetism had not been, from its very nature, destined ultimately to share the fate of every popular delusion. Fortunately however for science, Mesmer's operations were deemed worthy of the attention of government; and on the 12th of March, 1784, a committee, consisting partly of physicians, and partly of members of the royal academy of sciences, was appointed by the king to examine thoroughly the principles of the new magnetical system. At the head of this committee was the celebrated Dr. Franklin; and the individuals united with him in the inquiry were, Majault, Le Roy, Sallin, Bailly, D'Arcet, De Bory, Guillotin, and Lavoisier. These philosophers immediately entered on the discharge of the duty which had been intrusted to them, with all the judgment and assiduity which it was natural to expect from men so eminently qualified for the task. Mesmer refused to have any communication with this committee; but M. Deslon, the most considerable of his pupils, consented to disclose to them the whole principles and practice of his master, and to assist them in all their investigations.

Accordingly, the commissioners, after having made themselves acquainted with the theory of animal magnetism, as it was professed by Mesmer, witnessed each of them repeatedly, its effects in public, when administered by Deslon; they submitted, in private, to be magnetised themselves; and they magnetised others in a variety of circumstances. The final results of their inquiry were communicated to the king, on the 11th of August, in a report which was drawn up by Dr. Franklin, and which will be read with admiration, as long as the history of the human mind affords interest to the moral philosopher or the physiologist. The animal magnetic fluid was pronounced to have no existence; and compression, imagination, and imitation, were shown to be the true causes of the effects attributed to it. "The curious and interesting inquiries of M. Thouret," say the commissioners, “have convinced the public, that the theory, the operations, and the effects of the animal magnetism proposed in the last age, were nearly the same with those revived in the present. The magnetism, then, is no more than an old falsehood. The theory, indeed, is now presented (as was necessary in a more enlightened age) with a greater degree of pomp; but it is not, on this account, the less erroneous."

This interesting report was translated into English, with an historical introduction, in 1785; and it is from this translation, which is respectably executed, that the preceding detail has been almost verbatim extracted. It is very important, however, to mention, that in addition to this memoir, which was obviously meant for the public eye, the commissioners deemed it their duty to communicate a private report to the king; in which, with a laudable solicitude for the morals of the sex, they disclosed certain circumstances, accompanying the administration of the magnetism, in the highest degree unfavourable to the purity of the female feeling and character, and which, by designing individuals, might be rendered subservient to purposes of the most criminal profligacy. This secret memoir has since been made public. An exposure so complete, accomplished by men whose integrity and talents were acknowledged over the whole of Europe, speedily produced the effects that were to have been expected from it. In a few months, Mesmer and his animal magnetism were forgotten.

Since the overthrow of this system, the most remarkable popular delusion which has prevailed, is the belief in the influence of the metallic tractors of Perkins. With how much talent this deception was exposed by Dr. Haygarth and his scientific friends, is generally known. To this most able and intelligent physician, physiology is indebted for a series of experiments, displaying in a manner still more striking perhaps than had hitherto been done, the influence of powerful emotions on the corporeal frame. G. Edinburgh, 1st Sept.

ART. VII. Of the Dissemination of Plants. From the French of

M. C. F. Brisseau Mirbel.

[From the Journal of Science and the Arts.]

BY dissemination, we mean to express the spontaneous dispersion of the seeds of the vegetable creation; an event, which, while it brings to a close the yearly round of the vegetative functions of the individual, becomes the means of giving perpetuity to its race. When completed, the organs of the plant in which existence surpasses one year, tend visibly to a state of inactivity, and in that where this concludes with the year, to decay; being there in fact the first stage of dissolution. When we see the fruit separate from the parent-stem, its seams begin to open, the ligatures of the seed detach themselves from the placenta, we are not to place these appearances to the account of the energy of the vital principle; but on the contrary, to view them as the certain indications of its having ceased in that portion of the vegetable where they occur. Fruit undergoes the destiny of the leaf in autumn, and is quickly reduced within the control of those laws which govern all inorganic matter. If, of a succulent pulpy nature, the fluids ferment and turn sour, the texture collapses and the whole is dissolved by putrefaction; if of a ligneous dry consistence it follows precisely the course of the wood or the leaf in which vegetation has ceased.

In animals the affection they bear their offspring, the instinct they are endued with for its protection and succour, their strength, their courage, their address, are all so many means of insuring the perpetuity of their races; but to vegetables, sensation and the sources of spontaneous movement have been denied, and yet even here we see countless races appear before us on each revolving year, such as they appeared in the first days of their formation. Let us turn our attention to the causes of this wonderful stability in the races of vegetables.

The most efficient is without doubt the prodigious fecundity they are endowed with. Sir Kenelm Digby tells us, that the fathers of the congregation of La Doctrine Chrétienne at Paris, had in their possession about the year 1660, a single barley-plant with 45 straws producing in the aggregate 18,000 corns of barley. Ray counted 32,000 seeds in the heads of one plant of poppy, and 360,000 on one tobacco-plant. Dodart recounts of an elm, that it produced 529,000 seeds. Yet none of these vegetables are among those of the foremost ranks in the degrees of fecundity. The number of seeds borne by a plant of Begonia, or Vanilla, but above all by a fern, confounds calculation.

Although many kinds, like those of angelica, fraxinella, and coffee, quickly spoil, and require to be sown almost as soon as ripe; yet the far greater proportion preserve the germinating faculty for years and even for ages. We have ourselves recently witnessed the growth of the seeds of a kind of kidney-bean which had been taken from the herbarium of Tourneforte. Home sowed with success barley that had been gathered 140 years. Wheat has been discovered in subterraneous hoards, which had been lost

and fotgotton for time out of mind, in as perfect a state as the day it was reaped.

Insects, birds, and four-footed animals are the great destroyers of seeds; yet their abundance is such as prevails over the voracity of their consumers; while some are defended from all risk by the hardness of their coverings, or the thorns which arm them, or the acrid and corrosive juices with which they are impregnated.

Spontaneous dissemination favourable to the development of individual plants by preventing the too great accumulation of seed within a too narrow compass, is carried on in various ways. In the balsam, catchfly, fraxinella, sand-box-tree, &c. the valves of the seed-vessel open with a spring that projects the contents to a distance from the parent-plant. The gourd of the spirting cu cumber, by a contraction which takes place at the moment of its fall, darts out the seed along with a corrosive fluid by a vent formed as it quits the stalk. The seed of the wood-sorrel is contained in an extensile arillus or separace pouch, which dilates as the seedvessel grows, but at last the power of extension ceases in the pouch, when it bursts and shoots out the seeds by an elastic effort. Plants of a lower degree in the scale of organization, such as the mushrooms, have their peculiar means of disseminating the particles destined for their reproduction. For instance, some of the species of Peziza impart a vibratory motion to the cap or cover which bears their seed when that is ripe. Puff-balls, also of the mushroom-tribe, burst at the top like the crater of a volcano, and the seed is in such quantity and so fine that when it escapes it has the appearance of a volume of smoke. The capsules of ferns likewise open with a spring, an effect of their contraction in drying up when ripe. A like cause gives motion to the cilia or inner fringe which surrounds the urns or seed-vessels of mosses. But although such partial phenomena, may attract our curiosity, they act only a very subordinate part in the grand total of dissemination. There are other more general and powerful causes to be mentioned in this place.

Many seeds are as fine and volatile as the dust of the archer; the winds carry these away to scatter them on the plain, the mountain, the building, and in the very depth of the cavern. No place seems closed against the intrusion of the impalpable seeds of the various sorts of Moulds (Mucores.)

Heavier seeds and fruits are furnished with vings, which support them in the air, and serve to waft them through great distances. The seed-vessel of the elm is surrounded by a circular membranous wing; that of the ash is terminated by one that is oblong. The keys or seed-vessel of the maple has two large sidewings. The seeds of the fir, the cedar, and the larch are furnished with a wing of great fineness. The peduncle of the capsule of the lime-tree adheres to a kind of broad bracte which plays the part of wings.

The sepa

The seeds of syngenesious plants are furnished with a feathery crown or aigrette, and look like small shuttle-cocks. 6

VOL. XI.