Imágenes de página
PDF
ePub

pened to be the bour of dinner, were thinned by the desertion of young men thronging to behold him. The comparative seclusion of the last part of his life accounts for the editor's assertion nunquam se vidisse Virgiliuin,' though he was contemporary and resident with him in Cambridge more than twelve months.

Mr. Gray was a systematic as well as a severe student-he drew not from the fountain of literature only, but from the purest, the most copious, and the most remote.--His habits and his opinions were at the greatest possible distance from those of the being who, in the present general diffusion of knowledge, is styled 'a well-informed man.'

Mr. Gray always considered that Encyclopædias and Universal Dictionaries, with which the world now abounds, afforded a very unfavourable symptom of the age in regard to literature.- Dictionaries like these, he thought, only served to supply a fund for the vanity or for the affectation of general knowledge, or for the demands of company and conversation.'

This was perfectly right-profound and original knowledge on any subject can scarcely be produced in society, unless it be selected for the purpose.

The subjects of his pursuits, as well as the authors from whom be sought them, were selected with that fastidious exactness, which marked every habit of his life.

• Mr. Gray was accustomed to say that he well knew from expe« rience, how much might be done by a person who would have recourse to great original writers only; who would read in a method, and would never fing away his time on middling or inferior authors.'

In the present state of dissipated and superficial reading, the importance of this sentiment is daily increasing. Those who read only to talk of books, and are wont to estimate their own attainments or those of others by the number rather than the character of the volumes they have turned over, may learn from such examples, that it requires a process the very reverse of their own to attain to clearness or solidity of knowledge, to impregnate genius with the seeds of future excellence, and to brace the understanding by habits of rigorous and athletic exercise, through the united powers of which great original works can alone be produced, and great eminence be attained in the narrow compass of human life. Constituted as the literary world is at present, there is fortitude as well as dignity in remaining ignorant of the art and the subject of literary snall-talk.

Mr. Gray's profound acquaintance with the higher Tuscan poets,' whose genius partakes so largely of the lofty character of the Grecian muse, bas drawn' some excellent observations from the editor, whose influence we trust will not be unavailing in reviving that noble school, to which, however neglected by the tame spirit of our poets and critics in the 'Augustan age of Addison,' Spenser, Milton, and Gray, have been so deeply indebted. On this subject no living writer is better qualified to speak with authority and decision than Mr. Mathias. Let every young aspirant to the character of a critic or a man of taste read and receive with respect the following admirable stricture.

"From disingenuous hints, from attempts to resolve the character, the merits of the language of Italy into opera airs, and from the perpetual ridicule with which the English Spectator so unworthily and indeed so ignorantly abounds on this subject, an effect has been produced which has bitherto been fatal to its credit and its cultivation in Great Britain. But it must be remembered that at that period the star of French literature was lord of the ascendant, and that all the bolder and more invigorating influences which had descended on Spenser and on Milton from the luminaries of Italy were now no more. We are now once more called upon, as in the name of an august triumvirate, by Spenser, by Milton, and by Gray, to turn from the unpoctical genius of France, and after we have paid our primal homage to the bards of Greece and of ancient Latiuin, we are invited to contemplate the lite. rary and poetical dignity of modern Italy. If tbe influence of their persuasion and of their example should prevail, a stiong and steady Jight may be relumined and didused amongst us, a light which may once again conduct the powers of our rising poets from wild whirling words, from crude, rapid, and uncorrected productions, from an overweening presumption, and from the delusive conceit of a pre-established reputation, to the labour of thought, to patient and repeated revision of what they write, lo a reverence for themselves and for an enlightened public, and to the fixed unbending principles of legitimate composition.'

With this golden sentence, which unites the glow and energy of Longinus, with the depth and precision of Aristotle, we dismiss the present article, earnestly commending so seasonable an admonition to the attention of those who fondly imagine that genius without taste, wildness without judgment, and invention without care and without caution, will ever produce a work, destined like those of Gray, of Spenser, and of Milton, to survive the cheap applause of modern and capricious fashion.

Art. IV. Elements of Agricultural Chymistry, in a Course of

Lectures for the Board of Agriculture. By Sir Humphry Davy, LL.D. F.R.S.L. & E. V.P.R.I. &c. &c. Second edition, 8vo. London. 1814. pp. 500; with 10 plates.

M

UCH has been said by the learned and the unlearned for and 11 against the advantages of the theoretical cultivation of agriculture, as an object of national encouragement. The benefits of expe

rimental improvements of all kinds are very likely to be outweighed at first by their inconveniencies, whatever may be the skill and caution of the persons concerned in them; and it is natural that an ignorant or prejudiced observer should be at least as strongly impressed by the instances of failure as by those of success, and should be encouraged by the supposed accuracy of his own observations on the progress of others, to persevere in inveterate errors of various kinds, which more candour and more humility might possibly have enabled him to correct. The enlightened author of the present work has very truly observed, that the frequent failure of experiments, conducted after the most refined theoretical views, is far from proving the inutility of such trials; one happy result, which can generally improve the methods of cultivation, is worth the labour of a whole life; and an unsuccessful experiment, well observed, must establish some truth, or tend to remove some prejudice.

On the other hand, it has been frequently remarked, that the public of Great Britain not immediately connected with the landed interest, bas felt no other effect from the magnificent scale, on which the modern improvements of agriculture have been conducted, than the limitation of the supply of the table by an extravagant enhancement of the price of provisions, the curtailment of the enjoyment of rustic scenery by the progress of enclosure, the depression of gentlemen and noblemen into swineherds, and the elevation of a new order of uneducated beings into comparative opulence.

But that partial evils may have arisen from widely extended improvements, is no proof that the benefits on the whole have not preponderated. If our population has increased, it is of urgent necessity that a greater supply of food should be procured for its consumption; and if the improvements in agriculture have rendered it possible to obtain a greater quantity of food independently of foreign supply, it is natural and just that the farmers concerned in raising it should be enriched ! if enriched, they must be less dependent on the immediate demand of a purchaser, and the prices must be somewhat advanced; unless indeed the apparent increase of prices is to be attributed to the depreciation of the value of the circulating medium, which is by no means an impossible supposition. We do not profess any very high respeci for the intellectual dignity of the mechanical and servile pursuits inseparable from the occupation of the mere agriculturist, bow. ever they may be combined with superiority of talents and elegance of manners; but it is happy for many that such a combi nation is practicable; that without any degradation of their rank and consideration, the idle may find some amusing employ neat. and the less opulent some source of additional income, in devoting a portion of their time and attention to the original occupations of the heroes and patriarchs of remote antiquity.

Should the public have been disposed to form its expectations of the excellence of this work, from the unexampled success which has attended the former labours of the author in philosophical chymistry, it is probable that some disappointment may have been felt by many of its readers. We have however no right to demand from an individual that he should be uniformly fortunate; although we are persuaded that such a philosopher as Sir Humphry Davy can on no occasion be otherwise than respectable. In the experimental pursuit of general chymistry, an investigator is at liberty to follow those paths of inquiry which offer him the fairest prospects; but where his object is precisely limited to a given point of immediate utility, it is not in the power of human intellect to command a certainty of striking improvement. If however a sufficient store of information is furnished, to give employment to a thinking mind, and to enable it to pursue its own researches, without tempting it to advance rashly upon principles merely speculative, the end of such a publication is in a great measure answered : and so much as this, and more, the present work appears very successfully to have effected.

Of the eight lectures which it contains, the first is a general introduction to the subject ; the second an outline of the principles of physical science, especially as affecting vegetables; the third is devoted to the structure of plants, and the chymical properties of the substances which they contain; the fourth relates to soils and their analysis; the fifth to the atmosphere, and to the functions of vegetation; the two next to vegetable and mineral manures, and the last to the effects of burning and irrigation, and to the economy of crops.

crops. An appendix contains the results of an elaborate series of experiments on the nutritive matter afforded by grasses, performed at Woburn by order of the Duke of Bedford.

The first and second lectures, however well adapted for the information of the audience to whom they were addressed, and of the readers for whom they are intended, cannot be expected to contain much of novelty or of scientific interest. In the third the doctrine of the circulation of the sap is stated, according to the theory and experiments of Hales, Grew, Darwin, Mirbel,

and especially of Mr. Knight. The ascent of the sap through the alburnum, its modification by the action of the air, and by other circumstances to which it is exposed in the leaves, and its descent through the bark, are considered as preparatory to the formation of the cambium,' a mucilaginous fluid found between the bark and the alburnum, which is supposed to be a mixture of the

[ocr errors]

ascending and descending sap, affording, by a sort of precipitation, a concrete substance, which constitutes the new wood and bark. Sir H. Davy infers from the late observations of Mr. Palisot de Beauvois, as a partial exception to this theory, that the sap may be transferred to the bark, so as to exert its nutritive functions independent of any general system of circulation :-in the case of the maple and the lilac, small annual shoots were produced in the parts where the bark was insulated :' at the same time the growth of the bark in such cases appears to bave been extremely limited.

The author is disposed to adopt Mr. Knight's conjecture respecting the use of the silver grain, or radiating fibres of the wood, in propelling the sap, by its alternate expansions and contractions, depending on the daily changes of temperature: but we cannot say that we think any thing is gained by this conjecture. It has not been shown, or even rendered probable, that the silver grain has any powers of expansion materially different from those of the other parts of the vegetable ; and no attempt has been made to enable us to imagine in what manner this alternate expansion and contraction, if it actually took place, could operate at all upon the sap, much less how its magnitude could by any means be adequate to the production of such a force as would be required. In short, we must be contented, for the present, with confessing our total ignorance of the means by which the sap is propelled, being only assured that every theory, which has yet been advanced to explain it, is without foundation. As, however, the roots must attract moisture, and absorb it into their pores, with a certain force, whether of a mechanical, chymical, electrical, or vital nature, it is not impossible that the new substance, thus attracted, may simply urge onwards the former contents of the vessels, as a condition indispensable to its introduction; and it appears to us that this conjecture, if it does not afford much of a satisfactory explanation, is at least liable to no positive objection. The evaporation from the leaves must also tend to co-operate in promoting the ascent of the sap where the natural connexion is preserved, since it must produce a capillary suction so much the more powerful, as the tubes concerned are smaller, and consequently capable of drawing up the sap to a height almost unlimited; but not of forcing it upwards in the manner that the sap of vegetables is forced up in experiments similar to those of Dr. Hales. The remainder of the lecture is principally chymical: we shall only extract the result of one process lately discovered.

Mr. Cruikshank, by exposing syrup to a substance named phos. pburet of lime, which has a great tendency to decompose water, converted a part of the sugar into a matter analogous to mucilage: and Mr. Kirchof, recently, has converted starch into sugar by a very simple

« AnteriorContinuar »