The existence of PORES IN THE CUTICLE is far from being proved. Fontana speaks of serpentine vessels seen in it by the microscope; but M. Humboldt, who has made experiments with a microscope magnifying 35,200 times, asserts that these are folds and not vessels; he could not discover folds in the cuticle when magnified 312,400 times.-In what manner then is the matter of perspiration transmitted through it?

M.M. Bayle and Laennec attribute the developement of ACCIDENTAL STRUCTURES to a particular and unknown disposition of the animal economy, and consider the causes commonly assigned only as occasional circumstances favouring the action of this disposition. In other words, they confess their entire ignorance of the causes. M. Broussais, on the contrary, considers these productions as constantly resulting from inflammation, and the combination of albumen in different forms, with the structure of the body, according to their nature, and the degree of excitement. Meckel considers the changes as depending on an aberration of the nutritive processes, and the effusion of an albuminous fluid. M. Beclard divides accidental structures into four-tubercles, scirrhus, cancer, and melanose.

Such are a few of the interesting details furnished in this able continuation of the Anatomie Générale. We should have been much more particular in our analysis, had we not foreseen that all who possess the original work, and who are interested in the progress of the science, will add these Additions of M. Beclard to their libraries. We have, however, given so much of what is most important in the book, that those who cannot procure it, may at least have, in our abstract, the better parts of it; and, in our future articles, we promise not to lose sight of the useful illustrations, which we shall always be proud to borrow froin M. Beclard.

DECANDOLLE, LINK, AND SPRENGEL, ON THE PHILOSOPHY OF PLANTS, AND THE UTILITY OF BOTANY.*

It is a great mistake, though it is a very prevalent one, that it is useless for professional purposes to study any part of Botany,

* Théorie Elémentaire de la Botanique. Par A. P. Decandolle, à Geneve, 2d edit.

but what is strictly medical. By going upon the principle on which this mistake is founded, we could demonstrate, that even the knowledge of medicinal plants is almost useless to the physician, to the surgeon, and even to the apothecary; for it is but seldom that plants are fresh collected by them, or under their inspection, and seldom that they are seen by them till dried, or otherwise prepared for the market; and since this is so, of what use to them can a knowledge of the Linnæan descriptions and distinctions ever become, though they be treasured up with care in the earlier years of study? Of what use to the profession in this country, is the most accurate Botanical knowledge of convolvolus jalapa, callicocca ipecacuanha, or smilax sarsaparilla, when those plants are never seen here? The minute descriptions of the species and varieties of cinchona by Aylmer Bourke Lambert, may, no doubt, be very useful to the transatlantic collectors of bark; but they will prove to be a fallacious guide to the purchaser of bark when collected. The practically useful knowledge of this sort can only be learned in the warehouse and in the shop. It must be learned, however, though botany can never teach it; for the best botanists would here find themselves altogether at fault and out of their sphere. In this view, therefore, the study of medical botany itself appears to be of small value; and everybody will allow that the mode of prescribing, and the various doses of medicines prepared from herbs, which are introduced in works on Medical Botany, are wholly out of place, rarely consulted, and never trusted to. These subjects, indeed, have nothing to do with Medical Botany, and are only introduced to conceal the meagreness of the stricter botanical parts, by spicing them with scraps from herbals and pharmacopeias.

The botanical study of MEDICINAL PLANTS may, however, be sometimes useful to the country practitioner, who may find it the most eligible way to collect his own digitalis, hyoscyamus, and conium, fresh from the field; and still more so to those whose engagements lead them to remote parts, where medicines cannot be otherwise procured; and where they may be necessitated to discover the medicinal properties of plants wholly new

Grundiehren der Anatomie und Physiologie der Pflanzen. Von H. F. Link, Berlin..

Von der Natur und dem Bau der Gewachse;—und, Anleitung zur kenntniss der Gewachse. Von Kurt Sprengel, Halle." Elements of the Philosophy of Plants. By A. P. Decandolle, and K. Sprepgel. Translated from the German, Svo. pp. 520. 8 plates. Edinburgh, 1821.

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to them. In such cases it ought to be carefully noted, that the poisonous property of unknown plants, cannot well be known by their effects on the inferior animals. The goat eats greedily of the noxious water hemlock, (cicuta virosa); and the partridge of North America feeds with impunity on the poisonous seeds of the Kalmia.

In these points of view, the study of botany is certainly useful. But its chief value to a medical man is, as we conceive, its indirect INFLUENCE on his HABITS of observation and minute distinction. Botany cannot be studied at all, even in its rudiments, without the most accurate scrutiny of minute, and often almost imperceptible differences; it cannot be studied at all, without an exact knowledge of the logic of method and distinction. Now this minute observation of differences, and the power of grouping them, are qualifications indispensably essential to the practitioner in distinguishing the symptoms of diseases, and in grouping them into classes. It may be said, indeed, that this is rendered unnecessary by following an accurate system of Nosology; but all who have carried such a system to the patients' bedside must have soon perceived its imperfections, and must feel strongly that no nosological system, however well arranged, can ever supplant the ready habit of discrimination which we are sure the study of botany is better calculated to establish, than any other scientific pursuit. Besides, it can be pursued in the earlier years of study, when more complicated knowledge cannot be understood, and the important habits which we have mentioned can then best be indelibly stamped upon the mind.

Those, however, who reject this view of the utility of botany, and are inclined to look upon the study of the Linnæan system in particular as a mere waste of time, in parroting a long catalogue of barbarous terms, and names which are daily changed and changing by the spirit of innovation, cannot refuse to allow the utility of studying the PHILOSOPHY OF PLANTS, in their mode of germination and growth, and in all the circumstances connected with their life, in health and disease. This bears so closely upon the study of the animal system, and may in so many points lead to useful inferences and important discoveries, that it ought to form a proportionate part of medical study, though we are sorry to be forced to say, that, so far as we know, it is at present but partially pursued. We have not a doubt that this neglect has originated in the barren and lifeless details introduced into the science by Linnæus; for in former times, when botany was not a mere index of words, when Dioscorides, with all his errors and his fables, was the oracle of the schools, it formed a very prominent part of medical education, as we

undertake to prophecy it will form again, since the defects of the Swedish school have become glaringly apparent; and since the study is now beginning to be pursued, as it ought, experimentally and philosophically. Now that the researches of Grew, Malpighi, Lewenhoeck, Saussure, Du Hamel, and Hales, which were in a fair way of becoming eclipsed by the locust-like clouds of names from Upsal, are again coming into importance, and, are followed up by so many distinguished living philosophers, we hope that the study will be stripped of its repulsive barrenness, and will, by its utility, attract the general attention of the profession. This we shall endeavour, as far as we can, to promote, and shall, in the short space which we can here afford, give a small specimen of such details as appear interesting from the able works before us.

As we cannot afford room for systematic regularity, we shall begin with the DISEASES OF PLANTS, because it is a subject which is seldom brought into prominent notice in the elementary. works. These diseases are chiefly produced by external, or hereditary causes, and among the first, the greater number arise as amongst animals, from superabundant food or other luxuries. The most commonly observed instance of such diseases, is that of flowers becoming double, as in the rose, daisy, columbine, ranunculus, and many others, in which the too abundant supply of nourishment converts the calyx, nectaries, and stamens into petals, frequently preventing altogether, the formation of seed. Muller observed the curious fact, that the nectaries in such cases sometimes supply the place of the organs of fructification, (Verhandlungen der Gesellschaft, &c. I. 214.) The doubleblossomed cherry often gives out from the centre of its flower a leaf in miniature, and the whole spike in the common waybread, (Plantago major), is often converted into a leafy pyramid. Frequently also, a flower will send off others from its disc or centre as in the proliferous pink, and the daisy, called by gardeners the hen and chickens. We have seen an instance of this in Dactylis glomerata, though in wild plants it is rare to meet with such diseases of luxuriance. We have once or twice seen it in the daisy, ladies-smock (cardamine pratensis,) and marsh-marigold (caltha palustris.) Of this last plant we gathered, several years ago, at Catrine, Ayrshire, a specimen, having one of the petals growing on the flower-stalk, about an inch below the blossom. It seems often to arise from a similar cause, that flowers are either converted wholly or partially into leaves, as we have seen in one instance of a wild Leucojum æstivum; and as has been observed by Bernhardt, in Colchicum Autumnale, (Romer. Archiv. II.) and Hesperis matronalis. It is luxurious

nourishment also which causes leaves to subdivide, or to curl at the edges, as in solanum tuberosum, scolopendrium officinale, and fraxinus excelsior. (Sprengel, 413.) Fruits sometimes give out leaves, such as the pear.

The cause of the white, silvery, or golden spots and streaks seen on leaves, and sometimes admired, as in holy, ivy, agave, and mint, is not well known. That these are not natural, appears from the fact, that the variegation cannot be propagated by seed, and that the discoloured portion of the leaf does not exercise the same function as the green portion in regard to the oxygen of the atmosphere, as was experimentally proved by Sennebier. (Physiol. Veget. IV. 273.)

In the case of insects and parasitic fungi, and other plants producing disease, it is worthy of remark, that a diseased tendency in the plant seems to favour the production, or at least the increase of these enemies. This we believe holds equally true in the case of hydatids, and worms in the human system. On this principle bushes which grow upon an unfruitful soil, are more apt to be covered with lichens than those in gardens and shrubberies. The same is the case with the leprosy, or scab which Giovene informs us destroys the olive trees in Italy. (Opuscoli Scelti, XIII. 106.).

One of the most common and most destructive of these parasitic diseases is BLIGHT, which, like many other subjects, has been actually explained into obscurity; for supposing that it could only be one disease, and have only one cause, circumstances distinctly opposite have been confounded and identified, in the same manner as we have above remarked with respect to amaurosis. Sir Joseph Banks, in his paper on blight, refers the rust blight to a minute fungus, the seeds of which, as they float in the air, enter the pores of the epidermis of the leaf, particularly when it is sickly, or they are taken in from the soil by the pores of the root. With all deference, however, to the respected author of this theory, we must say that to us it appears fanciful and gratuitous. The existence of the fungus, indeed, is proved, but how its seeds came to the plant it attacks, we are wholly ignorant. One thing we know, it is very infectious, and if care be not taken, spreads rapidly. Sprengel is inclined, and we think plausibly, to attribute the disease to a morbid state of the juices of the plant, caused by some unknown circumstance in the seed, the air, or the soil. The cure of this sort of blight, indeed, by steeping the seeds in solutions of arsenic, and other steeps, shews clearly that it is not random seeds, flying about in the air which cause it; and the same is true of smut, which converts the grain into a black powder. The too dry or too