every part of the human frame is often formed in wax, or other plastic material; and where professional skill is not the object of study, may be quite adequate to convey a competent knowledge of the subject.

The use of coloured engravings in illustrating every department of animated nature, is a practice so general as hardly to require mention of its usefulness. In the subdivision of ornithology, our own country has produced a full share of splendid performances of this description. Indeed, imitative art has seldom displayed more brilliant achievements, than are witnessed in some recent publications in this branch of natural history.

Linear representations of animals are likewise capable of great spirit and vividness. A few happy strokes of the pencil will enable the most tardy imagination to fill up the space, and give life to the picture.

The next kind of illustrations, that of shaded and coloured figures, for maps and sections of country, appears almost indispensable to every course of instruction in this department. Without them, not only the varieties of mineralogical elements composing the different beds, would soon become confounded together in the minds of the auditors; but the relative situations of geological series-the displacement of strata-the results of recent deposits of matter over surfaces formerly upheaved-the "different positions of conformable and unconformable rocks, with numerous other facts and principles in this engaging science, would be nearly unintelligible.

As evidence of the usefulness of engravings to elucidate fossil geology, we need only refer to the splendid works of M. M. Cuvier and Brogniart, monuments at once of their authors' talents and industry, and of nature's ancient inexhaustible variety of organic productions.

What has just been stated respecting geology, may be applied with slight variations to the kindred science of mineralogy. The whole mineral kingdom may be displayed by well-chosen representative specimens, each of which may speak in turn to the eye of the inquisitive, and declare the character and relations of all within its district. An incidental circumstance (that of crystallization), connected with the study of mineralogy, is capable of being delineated in a manner fully intelligible, without the aid of solids. This department of natural history employs less frequently than almost any other, the aid of artificial models and coloured engravings; both because the actual specimens are for the most part easily obtained, and because the models and figures would fail to address correctly any other sense than sight, and it is well known that mineralogists depend on the touch, the odour, the hardness, and the specific gravity, no less than on the crystalline form, in making up their opinion of the composition of a mineral.

If we leave the range of natural history, and ask what de

pendence other branches of physical science place on the aid of visible demonstration, the chemist will direct us first to the laboratory of the manufacturer, or to that of the philosophical inquirer, surrounded by his instruments of research. He will next invite us to the exhibition of illustrative experiments, accompanied by statements of his own, to enable us to supply in imagination what cannot there be presented. Should he have occasion to describe a process, too long to be completed within his hour, we shall even be content to be shown the model of an apparatus by which it is performing; or he will have put in requisition the talents of a draftsman to multiply the varieties of form, and strengthen our conception of what he cannot actually exhibit. If we have occasion to speak of that which constitutes the pride of modern chemistry, the doctrine of different proportions, the matter will not be simply stated in words; we shall have either a linear diagram, a set of variouslycoloured cubes, or a Wollaston scale of equivalent to render all perfectly clear and truly definite. Perhaps, too, he might treat us to an explanation of this celebrated doctrine by means of certain symbols, which, though a little cabalistic at first sight, soon prove to be the most concise and beautiful method of presenting to the eye a vast amount of facts respecting chemical combinations.

In natural philosophy and mechanics, all the six methods before enumerated find constant application. From the workshop and manufactory, where the principles of the sciences are carried out into their practical development, to the abstract expression of those principles by help of the numerical, algebraic, and fluxional symbols, we have a series of appeals to the eye; by means of which we may impress the great truths of the science, or the varied modes of their application.

Thus, working models or movable diagrams, constitute the second class; solid models or patterns, the third; perspective representations, the fourth; and outlines, the fifth. We have already referred to the case of astronomy, as resting on the basis of observation. We might go into the walks of the fine arts, and witness the various means by which the painter, the sculptor, and the architect, endeavour to make known their achievements.

Here the two former would be found, appealing solely to the understanding and the taste through the eyes of mankind; and of the latter, so far as building assumes the character of fine art, and not merely of a useful trade, the same is preeminently true. Even music makes, at least, one most effectual and useful address to the eye by aid of the symbolic notes, without which many a modern performer would have been lamentably untuneful.

A most valuable application of the principle contended for, is found also in communicating the laws of elocution; the very

slides and inflections of the voice have by philosophical masters of this art, been happily depicted by lines and characters, which furnish to the eye something on which it can seize, to arrest and detain the fleeting modulations of sound. This enables us to fix the laws of utterance as regulated by construction, and especially to convey definite ideas of the rising and falling inflections; such are the most difficult duties, perhaps, which the rhetorician has to encounter.

Would time allow, we might further elucidate and exemplify the subject, by a reference to geography, history, the manners and customs of nations; the mythologies of ancient, and the superstitions of modern times. But there will sometimes be found matters of science, which we cannot bring before the eyes of the student. To carry conviction of their truth, or even conception of their possibility, we must, in the absence of actual ocular demonstration, adopt an analogous fact, or principle. A case has sometimes been supposed of an inhabitant of the tropics, who should be told that in other climates, water itself, that proverbially fugitive substance, was for a great part of the year in a compact, solid state, capable of being applied to the numerous purposes of impenetrable masses. That in this state, it forms a continuous bridge of mighty rivers-the gemmed splendour of the forest scene-the roofs of cabin for barbarous tribes the walls of palaces for fanciful monarchs—and a vast winding-sheet for all the glories of a departed year. How strong, it is said, must be his faith, to give credit to assertions so apparently absurd; and how should we overcome his incredulity? How, but by recalling to his mind some analogous change from the liquid to the solid state, particularly such as might result from a reduction of temperature. Should he ever have seen a saturated solution of any chemical substance, depositing its crystalline masses over the surface of a cooling liquid, his unbelief might be shaken, and the supposed fable of solidified water assume the air of a possible truth.

To certain subjects, we readily admit the mode of illustration now advocated is not applicable. Or if we attempt to make the application, we shall not only fail of rendering the subject more clear, but shall almost certainly obscure or degrade it. Of this kind are those questions which respect immaterial essences, their nature, relation, and mode of existence. The attempt to illustrate ethical and theological subjects by visible representation, is believed to have proved in most cases abortive, or to have utterly failed in its aim; if we admit that aim to have been the dissemination of truth. The conceptions of an individual mind on subjects of this nature, may doubtless be most vividly set before the eye, by visible representations. There was a period in literature, when most of the productions exhibited on the stage, were founded on the legends respecting saints, angels, and demons; and the actual representation is

said to have corresponded admirably with the extravagance of conception, in which their authors indulged.

But the uniform tendency is, to degrade whatever noble attributes are sought to be embodied, and to introduce grovelling and unworthy notions of the object of homage. The result is, a constant falling away to some species of idolatry; a substitution of some creature of sense, or at best some physical creature of the brain, for the true object of rational adoration.

Questions of abstract and metaphysical science, are seldom capable of being reduced to the form of visible representation; because, mind itself, which is the object of such science, as well as its faculties, is by nature wholly invisible.

The pencil has sometimes attempted to shadow forth certain states of mind, and particularly of moral feeling, by the representation of human forms in the attitudes and actions which those feelings or states of mind naturally induce. Thus, melancholy, with her pensive air-" her eye upraised, as one inspired;" hope, with her smile of anticipated joy-turned on vacancy; devotion, in her meek and supplicant attitude; imagination, with her rolling frenzied eye; fear, with her blanched cheek and quivering lip; cruelty, with her dark frown and stern regard, that gloats on blood; these, and innumerable other personifications of the passions or dispositions of our race, have been pourtrayed on the canvass, or stood forth from beneath the sculptor's chisel. But the misconstruction to which representations of this nature are liable, and which will perhaps, for ever, prevent the success of attempts to generalize the passions, indicates that the imitative art has strayed from its due sphere; and that its labour should be bestowed on real rather than allegorical subjects; on things that address the eye, and not on things unseen.

Hence, in a zeal for copiousness of illustration, it is to be regretted that implements and methods of elucidation are sometimes adopted, which, far from being the best that might be found, are but little if at all superior to verbal explanation. The cause of knowledge is actually retarded by frivolous and futile attempts to give, by any visible means, an appearance of exactness and demonstration to a subject which is confessedly level to all capacities, without any other explanation than a simple statement in plain and familiar language.

It is a fact greatly to be lamented, that in the first country of the world so little attention has been paid to this subject by modern educators. We do not possess, either as a part of any of our school systems, public or private, any systemized plan for teaching the elements of natural history or natural science, in a complete or comprehensive manner by means of the necessary tangible and visible illustrations. The subject has indeed been slightly touched upon in our infant-school systems; but in such an unphilosophical and incongruous manner, as to

be of little service even as a simple exercise of the knowing faculties; and nothing appears to us at this moment so absolutely necessary to improve and perfect our present miserable and inefficient methods. But it will be utterly vain and useless to attempt such a subject by bits and patches, it must be performed as a whole, in which its several parts have a mutual relationship with, and dependence on each other. He who unites in himself the true philosopher and teacher, may succeed in arranging and preparing a system for general adoption; such persons, are, however rare; many may make the attempt and will fail, as it has been the case in other instances. But we believe a long period will not elapse before all schools, both for rich and poor, will regard visible illustrations as an indispensable part of instruction, and the education of the Senses of high importance in the work of education.

DANGERS OF PESTALOZZIANISM.

The human understanding has been compared (we think by Hobbes,) to a drunken clown attempting to get on horseback, who, no sooner gets up on one side than he immediately falls over on the other. Thus, always feeble, frequently intoxicated, it vibrates successively from one extreme to another, and these vibrations are frequently performed in a kind of cycle or regular period of revolution, which brings it back again to the same train of thought and feeling which was long since abandoned. Every useful plan, and institution, and custom, and system of truth is liable to abuse and exaggeration; and in seeking to avoid the errors into which it has been imperceptibly led, it is often entirely abandoned. The reformer, who should but correct and amend, destroys-the building which need only to be repaired and improved, is torn down by. the zeal of those who perceive its defects, and the structure which is formed from its ruins is often too imperfect to afford a shelter, or too frail to resist a single storm; still in the course of ages there is an evident progress. It is by successive falls that our race, like its children, learns the art of walking in safety. We are not so easily deluded by an old error on its return from its long concealment in the obscurity of past ages, and faithful observers acquire at least the power of calculating the eccentricity and the duration of its course through our system, and are enabled to caution others against the dangers and apprehensions to which it may lead.

It is in this way, that science, and literature, and the arts, have experienced more than one decline and revival, and have attained a perfection which seems almost to annihilate distance and time, to penetrate the depths of the earth, and the atoms