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largely indebted, but may almost be said to owe its existence; it was by him that the “ Branch corresponding Committee at Rome” was organized; it was he that “ secured the sanction and approbation of the Roman government, and obtained the active and willing co-operation of the various learned bodies in that city and their erudite members, and acquired the aid of that powerful institution the College de Propaganda Fide.” Through him too, we may add, Professor Schlegel was afforded the most ample opportunities of learning the nature and objects of the Oriental Translation Fund during his recent visit to England. But though the Professor seems not to have availed himself of such advantages, we are assured that the honourable exertions of this nobleman to forward the cause of oriental literature, will be duly appreciated by the scholars both of England and the continent.
That an institution formed for such noble objects, and pursuing them with such enlightened zeal, should have avoided rather than courted notoriety, has always appeared to us unaccountable. To this cause alone we attribute the brevity of the subscription list, for were the merits of the Oriental Translation Fund thoroughly known, it would, ere now, have reckoned among its supporters every true lover of literature in the empire. It would also have received offers of literary assistance from those, who, though not deeply read as oriental scholars, yet possess learning which would illustrate oriental subjects. We should gladly see the Armenian writers illustrated by notes from the coteniporary Byzantine Historians; the late edition of Mirkhond mighi have been rendered more valuable if his statements had been contrasted with those of the Grecian writers. If, as we ardently hope, the whole of Mirkhond shall appear, we trust that the notes will illustrate the interesting era of the Sassanides from Procopius, Agathias, and the scarcely examined pages of the Talmud. All the literary men of England are interested in the success of the committee; all should be ready to tender it assistance, and by a judicious division of labours the future works will be reudered worthy of the age, the country and the institution. Perhaps the publication of some work, such as the beautiful romance of Hatim Tai, in a more popular form, or a selection of judicious extracts from the books on the committee's list, might call the attention of the great body of the nation to the pleasure, the interest, and the advantage that must result from the cultiva. tion of eastern literature; and prove the truth in modern, as well as ancient times, of the sentence so appropriately chosen by the committee for their motto-" Er Oriente Lur."
Art. III.-Physiologie Végétale, ou Exposition des Forces et des
Fonctions vitales des Végétaux, pour servir de suite à l'Organographie Végétale, et d'Introduction à la Bolanique Géographique et Agricole. Par M. Aug. Pyr. De Candolle. 3 tom. 8vo.
Paris. 1832. The great importance of vegetable physiology is sufficiently evident. The agriculturist and the horticulturist can expect increased success in their several departments, in proportion only as their practice reposes on an improving knowledge of the laws which regulate the phenomena of vegetable life. We have long wanted a work in which the more recent discoveries of modern observers should be collected, and their facts generalized; and the present volumes will be found to supply this want in a very efficient manner. The great progress which has been made of late years in this subject, could be known only from consulting the papers of various contributors, scattered through the pages of different scientific journals; and there existed no complete treatise to which the botanist might refer for an extensive and combined view of the several laws and principles which had been either clearly established or strongly suggested by a closer exainination of the complicated phenomena of vegetation than bad previously been attempted. On the continent, a long list of names might be enumerated of those who have devoted their attention to vegetable physiology; but in England, with a few rare exceptions, our best botanists have suffered their continental brethren to outstrip them in this superior department of the science. Whilst we possess at least a sufficient number of works exclusively devoted to “ descriptive botany," we can scarcely name one that makes any pretension to a close acquaintance with the more recent discoveries in " vegetable physiology.”* Mrs. Marcet's little work, entitled, “ Conversations on Vegetable Physiology,” is, indeed, excellent of its kind, and may be read with advantage and pleasure by every one who wishes to obtain a superficial knowledge of the subject. It professes merely to give an exposition of some of the leading topics of M. De Candolle's lectures, in his annual course at Geneva.
however, the views of De Candolle detailed by himself, and we turn to them in the full espectation of finding ample justice done to his subject. Not that we may expect to learn that all, or indeed that very many physiological questions have been settled by him, be
We have now,
* Whilst preparing this article we have received Professor Lindley's “ Introduction to Botany,” in which the physiology of plants forms the subject of one book. The well-known proficiency of this eminent botanist will satisfy every one that he has bere rendered an important service to this science.
yond the possibility of further cavil; on the contrary, the science is still so far in its infancy, that scarcely any of the most important laws and functions of vitality can be considered as fully understood. His work, however, is most valuable, in presenting us with a clear and explicit detail of the phenomena of vegetation, and a sufficient exposition of the various hypotheses by which different botanists have proposed to account for their existence. It is at once a compilation and a review of nearly every thing at present known on the subject. The work itself forms the second part of a complete “ Course of Botany,” which the author has for several years had it in his view to publish. The first volume of this course appeared in 1813, and a second edition of it in 1819, under the title of “ Théorie Elémentaire de la Botanique.” This was succeeded by two volumes, entitled, “ Organographie Végétale," in 1827. These three volumes completed the first part of the “ Course.” The present three, on “ Physiology," constitute the whole of the second part; and the author proposes to publish hereafter a third part, containing “ Botanical Geography,” and other departments not yet discussed.
All researches that are undertaken in the several departments into which the study of nature is divided, may be classed under one or other of two general heads. They are either such as are made for the purpose of ascertaining the sensible qualities" of bodies—as the materials of which they are composed, and their structure, whether internal or external; or else they are made with a view of discovering and estimating the laws which regulate the “ various forces" acting upon, or by means of, the materials of which those bodies are composed-such as alter their condition, or produce in them various kinds and degrees of motion. We say, therefore, that every branch in the vast study of nature has its " descriptive” and its "dynamical” department. The dynamical department of botany is denominated “ Vegetable Physiology," whose immediate object is to determine the precise influence which the mysterious principle called “Life” has upon the vegetable structure, under whatever conditions it may be placed. In his former treatises, our author had described the organs of plants, and their anatomy; in other words, he had shown us the construction of the machinery by means of which life is enabled to act, and to produce its effects; and in the present volumes he proceeds to show us this machinery in action. As, however, it seldom, if ever, happens that any single phenomenon in vegetation can be directly ascribed to an effort of "life" alone, but must also be considered partially dependent upon the simultaneous action of two other forces, “affinity” and “ attraction;" it is a problem of no small difficulty to determine, what portion of the
effect ought to be ascribed to each of these three forces independently of the other two. In all cases where a single force only is known to operate, its laws may be ascertained with precision, from the direct results which it produces; but wheu two combined forces produce a result, it is necessary that we should first ascertain the effect that would be produced by one of them when acting alone, before we can hope to appreciate that which is due to the action of the other. Now, the laws of “ attraction” have been ascertained from the examination of the phenomena of the heavenly bodies, whose motions depend upon the immediate action of this force only. The laws of " affinity" are not yet ascertained ; and, consequently, we cannot expect to determine, with perfect certainty, what those other laws may be which regulate the circumstances under which "life" is exhibited by the vegetable kingdom. When the physiologist would search for additional data for conducting his inquiry, and turns to the vital phenomena presented by animals, he finds his difficulties to be further increased by the presence of a “ sentient” principle, which is in them superadded to the three forces above mentioned. Since, however, it would be impossible to await the final result of future researches into the nature and laws of " affinity,” before we would proceed in our investigations of those which belong to “ life" itself, we must endeavour, as well as we can, to carry on the examination of each of these forces simultaneously ; being cautiously guarded not to ascribe to any effort of vitality what is actually due to the action of either of the two other forces; nor, on the other hand, be tempted to consider “ life" itself as resulting merely from their joint operation upon a previously organized body. Every fact, then, connected with the existence of life in plants, should be carefully weighed in a double point of view: first, to see whether it has resulted from the action of one or more forces; and, secondly, how far each of these forces may have been modified by the peculiar structure of the body acted on. For the tissue itself of which the vegetable structure is composed possesses certain peculiar properties, and these must be first determined, lest they should be mistaken for vital properties. The physiologist, then, ought first to ascertain, as clearly as the case will permit
, what portion of the result must be ascribed to the effects of attraction and affinity; what must be allowed to be the peculiar properties of the tissue itself; and, having abstracted these, he will arrive at what must be due to the specific action of the vital force.
In comparing vegetable with animal physiology, we find a striking analogy between many of the facts presented in each kingdom of organized nature; and since some departments of
inquiry are more advanced in the one than in the other, the two studies may mutually assist each other in arriving at the solution of many questions of general physiology.
There are three properties more peculiarly distinguishable in the tissue of which the elementary organs of plants are composed. These are “ extensibility,'
extensibility,” “ elasticity,” and “hygroscopicity.” These it possesses whether in the dead or living plant, and therefore so much of every phenomenon as may be explained by their action should be ascribed to the inherent properties of this tissue, and not confounded with the functions of “ life" itself. The cellular tissue of plants is enabled to accommodate itself to the development and growth of any organ, by its property of " extensibility,” up to a certain point, beyond which it becomes ruptured, and must then be considered as dead matter. Upon its “ elasticity” depends the action by which certain organs are maintained in particular positions, or by which they constantly return to such positions when any counteracting force is removed. Thus, in the common pettle, the stamens are curved forward in the early state of the flower, when they are held together by the anthers; but afterwards, as the filaments elongate, their elasticity alone is quite sufficient to dissolve the union of the anthers, and the stamens then fly back with violence and with a shock sufficient to cause the anthers to discharge their pollen. This particular movement therefore, and some others of a ke kind, must not be ascribed to any specific vital action, but merely to the elasticity of the vegetable tissue. The " hygroscopic" action of the vegetable tissue is very considerable, and indeed constitutes its most important property. It ought not, perhaps, to be considered as any other than a peculiar case of " capillarity,” where the pores which perforate the tissue are too minute to be capable of detection under the very highest powers of the microscope. It is most eminently conspicuous in the purest states of the tissue; as in the newly formed spongioles at the extremities of the root, and in the wood of the stem, We suspect, however, that De Candolle has in this latter instance confounded the action of the capillarity of the whole mass, originating in the presence of the intercellular passages, with the hygroscopicity of the tissue itself, and we can by no means assent to his explanation of gum and other matters being dislodged from the bark by an expansion of the wood, swollen by the hygroscopic action of the tissue composing it. Gums and resins, when secreted in superabundance, must necessarily be protruded externally, from the want of sufficient internal reservoirs appropriated for their reception.
After having noticed these three properties of the vegetable