want of knowledge and of capacity to command were so glaring, that scarce one of the chiefs, or princes, or prelates, who heard her in council or familiar conversation, appears to have retained beyond the few first days the slightest faith in her mission. At best they regarded her as a useful tool in their hands, from the influence which they saw her wield upon the army and the people. And herein lies, we think, a further proof of her perfect honesty of purpose. A deliberate impostor is most likely to deceive those on whom he has opportunity and leisure to play his artifices, while the crowd beyond the reach of them most commonly remains unmoved. Now the very reverse of this was always the case with Joan of Arc.

The fate of Joan in literature has been strange,—almost as strange as her fate in life. The ponderous cantos of Chapelain in her praise have long since perished-all but a few lines that live embalmed in the satires of Boileau. But, besides Schiller's powerful drama, two considerable narrative poems yet survive with Joan of Arc for their subject,-the epic of Southey, and the epic of Voltaire. The one, a young poet's earnest and touching tribute to heroic worth-the first flight of the muse that was ere long to soar over India and Spain; * the other full of ribaldry and blasphemous jests, holding out the Maid of Orleans as a fitting mark for slander and derision. But from whom did these far different poems proceed? The shaft of ridicule came from a French-the token of respect from an English-hand!

Of Joan's person no authentic resemblance now remains. A statue to her memory had been raised upon the bridge at Orleans, at the sole charge—so said the inscription-of the matrons and maids of that city: this probably preserved some degree of likeness, but unfortunately perished in the religious wars of the sixteenth century. There is no portrait extant; the two earliest engravings are of 1606 and 1612, and they greatly differ from each other. Yet who would not readily ascribe to Joan in fancy the very form and features so exquisitely moulded by a young princess? Who that has ever trodden the gorgeous galleries of Versailles has not fondly lingered before that noble work of artbefore that touching impersonation of the Christian heroine-the

*The Vision of Kehama,' and 'Roderick the Last of the Goths.' We have lately read 'Joan of Arc, revised, in the collected edition of Mr. Southey's poems, of which it forms the first volume. In his preface, dated May 10, 1837, he has these words, and few, indeed, are they who will read them unmoved :-" I have entered upon the serious task of arranging and collecting the whole of my poetical works. What was it, indeed, but to bring in review before me the dreams and aspirations of my youth! Well may it be called a serious task, thus to resuscitate the past. But serious though it be, it is not painful to one who knows that the end of his journey cannot be far distant, and, by the blessing of God, looks on to its termination with a sure and certain hope."

head

head meekly bended, and the hands devoutly clasping the sword in sign of the cross, but firm resolution imprinted on that closepressed mouth, and beaming from that lofty brow!-Whose thoughts, as he paused to gaze and gaze again, might not sometimes wander from old times to the present, and turn to the sculptress-sprung from the same Royal lineage which Joan had risen in arms to restore-so highly gifted in talent, in fortunes, in hopes of happiness-yet doomed to an end so grievous and untimely? Thus the statue has grown to be a monument, not only to the memory of the Maid, but to her own: thus future generations in France-all those at least who know how to prize either genius or goodness in woman-will love to blend together the two names-the female artist with the female warrior-MARY OF WURTEMBERG and JOAN OF ARC.

ART. II.-Organic Chemistry, in its Applications to Agriculture and Physiology. By Justus Liebig, Professor of Chemistry in the University of Giessen. Translated from the German MS. of the Author by Dr. Lyon Playfair. 8vo. London. 1840.

PROFESSOR LIEBIG has long enjoyed an European

reputation as one of the most profound and sagacious of chemists; and in particular has taken the lead, both by his personal labours and by those of the admirable school which he has formed in Germany, in those researches into the chemistry of the animal and vegetable kingdom which have, within the last fifteen years, created a new science, that of Organic Chemistry.

'Agriculture,' he says, 'is the true foundation of all trade and industry-it is the foundation of the riches of states. But a rational system of agriculture cannot be formed without the application of scientific principles; for such a system must be based on an exact acquaintance with the means of nutrition of vegetables, and with the influence of soils and action of manure upon them. This knowledge we must seek from chemistry, which teaches the mode of investigating the composition and studying the characters of the different substances from which plants derive their nourishment.'-Preface, p. vii.

When Sir Humphry Davy wrote on agricultural chemistry, Organic Chemistry was almost unknown. That happy genius did as much as could be done with the materials at his command, and established some principles of the highest importance. The work before us is an attempt to pursue the same path of inductive inquiry, with the aid of the more extended means which the present state of science affords.

Most of our readers are aware that the greater part of all vegetables consists of but four elements-namely, carbon, hydrogen, oxygen, and nitrogen; very often of the first three alone; while the remainder is composed of certain saline, earthy, and metallic compounds, which form the ashes that remain when vegetables are burned. The former are called the organic, the latter the inorganic elements of plants. Professor Liebig has demonstrated that the latter, although occurring in very small quantity, are yet as essential to the developement of the plant as the former; and it is obvious that the first inquiry, in such a work as his, must be as to the sources from which all these necessary constituents are derived, and the best means of supplying them.

With regard to the carbon of plants, the general opinion of writers on vegetable physiology, and of practical agriculturists, attributes its origin to the substance called humus, or vegetable mould, which is present in all fertile soils, and which is merely the remains of former vegetables in a state of decay. This substance, either alone or in combination with lime and other alkalies, is believed to be absorbed by the roots, and thus directly to furnish carbon for the plant. But this view has been shown by M. Liebig to be quite untenable; and he has demonstrated, by a most ingenious and convincing train of argument, that the carbon of plants is derived from the carbonic acid of the atmosphere. We are tempted to quote pretty largely on this point, both because this section affords an excellent specimen of our author's reasoning, and also because, in the economy of nature, the supply of carbon to plants is beautifully associated with the restoration to the atmosphere of the oxygen removed from it by the respiration of animals and other processes, and thus preserves the air constantly in the same state of fitness for the life of animals.

After proving, from the analysis of the properties of humus, that it cannot yield to vegetables, in the most favourable circumstances, more than a mere fraction of their annual increase of carbon, he proceeds:→

'Other considerations, of a higher nature, confute the common view respecting the nutritive office of humic acid (humus) in a manner so clear and conclusive, that it is difficult to conceive how it could have been so generally adopted. Fertile land produces carbon in the form of wood, hay, grain, and other kinds of produce, the masses of which, however, differ in a remarkable degree.'-p. 13.

Here follows a calculation of the average annual produce of one Hessian acre of average land, in the different shapes of wood, meadow-hay, corn, and beet-root: the land in the two latter cases being manured; in the two former, the forest and the meadow,

not

not manured. Notwithstanding the vast difference of bulk, weight, and shape, in these different forms of produce, the quantity of carbon in each is almost exactly the same; viz. about 1000 lbs. per acre. This interesting result, in the case of the forest, is derived from an account, on the best authority, of the quantity of wood annually cut for fuel in the admirably managed forests of Germany, without injury to the future value of the forest. This quantity may fairly be considered as the equivalent of the annual crop of an annual plant, such as corn, where the soil is judiciously cropped and not unfairly exhausted. In the cases of the hay, corn, and beet-root, the crop was simply weighed, and the amount of carbon ascertained by analysis.

'It must be concluded from these incontestable facts that equal surfaces of cultivated land, of an average fertility, produce equal quantities of carbon; yet how unlike have been the different conditions of the growth of the plants from which this has been deduced!

'Let us now inquire whence the grass in a meadow, or the wood in a forest, receives its carbon, since there no manure--no carbon-has been given to it as nourishment ;-and how it happens that the soil, thus exhausted, instead of becoming poorer, becomes every year richer in this element. A certain (and very large) quantity of carbon is taken every year from the forest or meadow in the form of wood or hay; and, in spite of this, the quantity of carbon in the soil augments-it becomes richer in humus.

It is said that, in fields and orchards, all the carbon which may have been taken away as herbs, as straw, as seeds, as fruit, is replaced by means of manure; and yet this soil produces no more carbon than that of the forest or meadow, where it is never replaced. It cannot be conceived that the laws of the nutrition of plants are changed by culturethat the sources of carbon for fruit or grain, for grass or trees, are different. It is not denied that manure exercises an influence upon the developement of plants; but it may be affirmed with positive certainty that it neither serves for the production of the carbon nor has any influence upon it, because we find that the quantity of carbon produced by manured lands is not greater than that yielded by lands which are not manured. The discussion of the manner in which manure acts has nothing to do with the present question, which is the origin of the carbon. The carbon must be derived from other sources; and as the soil does not yield it, it can only be extracted from the atmosphere.

In attempting to explain the origin of carbon in plants, it has never been considered that the question is intimately connected with the origin of humus. It is universally admitted that humus arises from the decay of plants. No primitive humus, therefore, can have existed; for plants must have preceded the humus. Now, whence did the first vegetables derive their carbon ?-and in what form is the carbon contained in the atmosphere?

These two questions involve the consideration of two most remarkable natural phenomena, which, by their reciprocal and uninterrupted

z 2

influence,

influence, maintain the life of individual animals and vegetables, and the continued existence of both kingdoms of organic nature.'-pp. 14-16.

The two phenomena here alluded to are the well-known facts that the proportions of oxygen and carbonic acid gases in the atmosphere are, and have long continued, stationary; notwithstanding the enormous quantities of oxygen withdrawn at every moment from the atmosphere by the respiration of man and animals, as well as by the processes of combustion and putrefaction; the whole of which oxygen is converted into an equal volume of carbonic acid gas, and returned in this form to the atmosphere: so that we should expect the carbonic acid to increase exactly in proportion as the oxygen, diminished, instead of the proportions of both remaining unchanged.

It is quite evident that the quantities of carbonic acid and oxygen in the atmosphere which remain unchanged by lapse of time must stand in some fixed relation to one another; a cause must exist which prevents the increase of carbonic acid, by removing that which is constantly produced; and there must also be some means of replacing the oxygen which is removed from the air by the processes of combustion and putrefaction, as well as by the respiration of animals. Both these causes are united in the process of vegetable life.

The facts stated in the preceding pages prove that the carbon of plants must be derived exclusively from the atmosphere. Now carbon exists in the atmosphere only in the form of carbonic acid; that is, in a state of combination with oxygen.

It has already been mentioned likewise that carbon and the elements of water form the principal constituents of vegetables; the quantity of the substances which do not possess this composition being proportionally very small. Now the relative quantity of oxygen in the whole mass (of vegetables) is less than in carbonic acid. It is therefore certain that plants must possess the property of decomposing carbonic acid, since they appropriate its carbon for their own use. The formation of their principal component parts must necessarily be attended with the separation of the carbon of the carbonic acid from its oxygen, which latter must be returned to the atmosphere, while the carbon enters into combination with water or its elements. The atmosphere must thus receive a volume of oxygen for every volume of carbonic acid which has been decomposed.'-pp. 18-20.

After some details, proving, from the experiments of Priestley, Sennebier, and De Saussure, that plants, when exposed to light, really possess the property of thus decomposing carbonic acid, and liberating oxygen, Professor Liebig adds :

The life of plants is closely connected with that of animals, in a most simple manner, and for a wise and sublime purpose. The presence of a rich and luxuriant vegetation may be conceived without the concurrence of animal life, but the existence of animals is undoubtedly de

pendent