their superior excellence as a manure. They acted empirically; and we could not desire a better proof of the great truth, that every discovery, legitimately inferred from observed facts, will sooner or later be found to coincide with the best practice and to explain it. We may add that we have seen letters from German agriculturists, cordially appreciating the principles developed in Liebig's work, as supplying them with that which they had earnestly sought for during their lives, but had long ceased to hope for; having found in the works of physiologists nothing but contradictory facts and baseless theories. With reference to the subject of manures, there are one or two principles which appear to us to flow naturally from Mr. Liebig's researches, and which are worthy of all attention from agriculturists. The first is, that since every plant extracts from the soil, and retains in its substance, only such inorganic matters as are essential to its growth, the very best manure for a plant must be the plant itself, in the form of straw, or even in that of ashes. We have seen how the ashes of wheat straw are, and must be, the best manure for wheat; but the principle must apply universally. Potatoes, for example, will be best manured with the ashes of potato-plants, which are singularly rich in phosphate of magnesia, the characteristic salt of the potato. Of course in this case, as in all others, any other ashes containing the same salt, or any other source of it, may be employed with equal advantage. We have had the pleasure of seeing the result of the use of pure phosphate of magnesia as a manure for potatoes; and we could not previously have imagined such astonishing crops as we then beheld. Now chemistry can easily produce this salt in sufficient quantities and at a low price, when it shall be wanted. Our strata of magnesian limestone, which alone is generally hurtful to plants, will thus furnish us with the means of adding to our crops of potatoes almost without expense. Again, when we reflect on the vast importance of nitrogen as an ingredient of grain, and on the fact that cow and horse dung contain very little of that element, we must see how essential it is not to waste any portion of liquid manure, the proper source of that portion of nitrogen which must be added to what is derived from the atmosphere before we can obtain rich crops of grain. But a still more important source of nitrogen is in the contents of our common sewers, which, from a barbarous ignorance, are commonly thrown into the sea. 'When it is considered that with every pound of ammonia which evaporates a loss of 60 lbs. of corn is sustained, and that with every pound of urine a pound of wheat might be produced, the indifference with which these matters are regarded is quite incomprehensible.' • The The powerful effects of urine as a manure are well known in Flanders, but it is considered invaluable by the Chinese, who are the oldest agricultural people we know. Indeed so much importance is attached to it by these people, that laws of the state forbid that any should be thrown away, and reservoirs are placed in every house, in which such matters are collected with the greatest care. No other kind of manure is used for their corn-fields. 'China is the birthplace of the experimental art: the incessant striving after experiments conducted the Chinese a thousand years since to discoveries which have been the envy and admiration of Europeans for centuries-especially in regard to dyeing and painting, and to the manufacture of porcelain, silk, and colours for painters. These we were long unable to imitate; and yet they were discovered by them without the aid of scientific principles: for in the books of the Chinese we find recipes and directions for use, but never explanations of pro cesses. 'Half a century sufficed to Europeans, not only to equal, but to surpass the Chinese in the arts and manufactures; and this was owing merely to the application of correct principles deduced from the study of chemistry. But how infinitely inferior is the agriculture of Europe to that of China! The latter is the most perfect in the world; and there, where the climate in the most fertile districts differs little from the European, very little value is attached to the (solid) excrements of animals.' Were the contents of our common sewers properly treatedmixed, for example, with ashes containing phosphates and with a slight excess of diluted acids, and then dried up so as to get rid of the water they contain, without permitting the escape of ammonia -they might readily be obtained free from all offensive odour, and in a form admitting of transportation to any distance. Such a mixture would surpass all manures hitherto tried, as it would contain precisely what is required to yield the richest crops of grain. By availing ourselves in such matters of the means offered by chemistry, we feel satisfied that in less than another half century we should leave far behind the empirical agriculture of the Chinese. Some such attempts have been made on the continent; and although, from ignorance on the part of the manufacturer, a great part, nay, in some establishments, the whole of the ammonia is expelled and lost in the process of preparation, yet the manure so prepared, acting by its inorganic constituents alone, has produced amazing effects. Our readers, we trust, are by this time convinced that the principles of rational agriculture are within the domain of science, and that from science alone, when called in to aid the zealous agriculturist, can we hope for real and permanent improvement. In the present work, Mr. Liebig has pointed out the path to be pursued, and has amply vindicated the claim of science to be considered considered the best guide, by correcting the erroneous views hitherto prevailing of the sources whence plants derive their nourishment, by developing the true causes of fertility in soils, and, finally, by establishing on a firm basis the true doctrine of manures. We do not, any more than the author himself, consider his work in the light of a complete treatise on the chemistry of agriculture; we look on it merely as an example of the proper method to be followed in producing such a work, and in this point of view we hold Dr. Liebig to be entitled to the gratitude of mankind. It is satisfactory to know that, of this very valuable work, the second English edition is already in the press, to be published at a cheaper rate; that two editions have been exhausted in French; that a third German edition has lately appeared, and that it has been reprinted in America. The author received the thanks of the British Association for his work; and Dr. Daubeny, the distinguished professor of agriculture at Oxford, who had undertaken to report on agricultural chemistry to the late meeting of the Association at Devonport, candidly acknowledged that he had nothing material to add to Professor Liebig's report, to which he referred. Professor Johnston of Durham has also afforded the best proof of the high opinion he entertains of it, by giving a valuable and interesting course of lectures on the subject, in which he has embodied and strongly urged on the attention of our northern agriculturists the principles established by Professor Liebig.* The translation before us, although generally accurate, is far from being elegant, and is occasionally obscure. In a few instances there are serious errors, which we believe must be attributed to haste in printing, as the volume was with difficulty got ready in time for the Glasgow meeting of the Association. We have no doubt that the second edition, now in the press, will be free from such blemishes. It is, however, a difficult task to give in a translation the true character of Professor Liebig's German style, ardent and energetic, often abrupt, but singularly forcible and impressive. *Mr. Johnston's lectures on this subject are still, we believe, in progress: they are printed as they are delivered. ART. 2 A VOL. LXIX. NO. CXXXVIII. ART. III.-Cola di Rienzo und seine Zeit, besonders nach ungedruckten Quellen dargestellt, von Dr. Felix Papencordt. Hamburg und Gotha, 1841. Cola di Rienzo and his Times, chiefly from unpublished Docu ments. A LIFE of Nicholas Rienzi, the hero of history, biography, tragedy, and romance, from sources hitherto unpublished, might be supposed, after the labours of Muratori and the other Italian antiquarians, an announcement rather tending to awaken suspicion than very ardent expectation. We, however, see no reason to question the authenticity of the documents brought to light by Dr. Papencordt-and most curious they are; as our readers will acknowledge by and by. But before opening them we must say a few words on the Tribune and his age. For Rienzi can be understood only in conjunction with his times. The secession of the popes to Avignon had not merely left an open field for an adventurer, like the Tribune, but had called forth and strengthened all those powerful sentiments and hopes on which he raised the fabric of his power. Rome all at once ceased to be the religious capital of the world. She retained, it is true, the shrines and the relics of the great apostles; and pilgrims still crowded from all parts of Europe to the city hallowed by these sacred memorials-to that which Petrarch calls the Jerusalem of the West. But the tide of homage and of tribute which flowed towards the throne of the successors of St. Peter, and constituted the wealth and the influence of Rome, now took another course. A mere delegate of the pope, usually the Bishop of Orvieto, occupied the chair of the apostle; all the ecclesiastical causes, with the authority which they tended to confirm, and the riches which they poured into the papal treasury-the constant influx of business which could not but be attended with great expenditure-the strangers from all parts of the world, thus brought together from various motives, either secular or religious -all now thronged the expanding streets of Avignon. Rome thus deserted, and degraded from her high ecclesiastical position, was thrown back, as it were, upon her earlier reminiscences. She had lost her new, and was ready to welcome whatever might recall her old supremacy. All the circumstances of the times continued to strengthen this sentiment, which blended with the wide-spread impatience and jealousy of the encroachments of the ecclesiastical upon the civil power. The Ghibelline spirit, which had been sternly suppressed by the alliance of the popes, first with the Norman, and afterwards with the Angevin sovereigns of Naples, was still brooding in dangerous secrecy in every part of Italy." In many many it was no attachment to a foreign, a German Emperor; but an earnest longing for the re-establishment of a supreme imperial power, the restoration of a Roman empire. This was intimately connected with splendid visions, which crossed all the nobler minds of the times, such as Dante's and Petrarch's, of the independence of Italy. And Rome might appear thus cleared as it were of the great fabric of ecclesiastical rule, in order to leave room for some new foundation of civil authority. The first dawn of the revival of classical tastes and studies which had been so publicly and so proudly welcomed in the coronation of Petrarch-the respect for the ancient monuments of Rome, which that great poet had endeavoured to inculcate, and which wrought so powerfully on the mind of Rienzi-strengthened the same tendencies. At the same time a very strong religious reaction was working, especially in the minds of the lower orders, against the temporal power of the popes, and of the clergy in general. The absence of the popes from Italy, the unpopularity of their desertion of their old seat of empire, allowed free scope for this new fanaticism. It was immeasurably strengthened by the rumours of the vices, the abominations, the base venality of the papal court at Avignon-vices and abominations which, even when Rome was in her high ecclesiastical pride, had obtained her the name of Babylon; and that name was now transferred (without any of the nobler and national feelings which still adhered to Rome) to a foreign French city. The Franciscan order, at least an active and very powerful branch of it (the Fratricelli or Spiritualists, with whom we shall hereafter find Rienzi in intimate connexion), not merely with their bare feet, and macerated forms, with their strict adherence to their vows of poverty, and their monastic retreat to the wildest recesses of the Apennines, afforded a striking, and no doubt widely effective, contrast to the wealth, the pride, and the magnificence of the papal court; but they likewise openly denounced the unapostolic, unevangelic union of temporal with spiritual power; proclaimed the advent, if not the actual commencement of a new period of the dominion of the Holy Ghost, in which monasticism was to prevail with all its strictest mortifications, its total self-denial, its absolute estrangement from all secular concerns. This new advent had been announced in visions and prophecies; had been preached in every quarter, and to every rank; and this religious Ghibellinism in many minds was blended with the deepest devotion to the ecclesiastical supremacy of the Holy See. The influence of this wide-spread enthusiasm perhaps at the commencement of his career affected but partially and indirectly the mind or the measures of Rienzi; though he subse 2A2 quently |