PREFACE. There are few tasks of more difficult accomplishment, than the one which an Author feels bound to undertake, when a performance which has engrossed much of his time, and to which he has probably directed his best energies, is about to be submitted to the public. Literary usuage appears, however, to have decided, that upon such an occasion, some prefatory observations are considered indispensable; but, while prompted by a natural desire to enter somewhat freely into the merits of that which has occupied his most earnest attention, the overwhelming apprehension of being thought egotistical, and the bare possibility of really becoming so, will often paralyze the Writer's well-intentioned efforts. In the present instance, I can truly say, that my incessant occupation from the hour I commenced this volume to the very eve of its publication, coupled as it has been with an anxious desire to render it worthy of public favour, have left me no time to consider what arguments would be most likely to fix the reader's attention to the following pages; in what terms I should entreat his kind indulgence; or upon what grounds I could venture to deprecate the severity of criticism. May I be allowed to say, that I have endeavoured to produce a work, which -while I am fully sensible of its numerous imperfections I trust, may be generally acceptable, and, I hope, extensively useful? Its design, though briefly, is not obscurely, stated in the title-page: and its contents, multifarious as they are, are so perceptible at a cursory glance, owing to the alphabetical arrangement, that it would be almost impertinent to trouble the reader with more than a mere reference to the general plan. A wonderful change has of late years taken place in the means adopted for the diffusion of a taste for literature and science. The talents and attainments of eminent Professors, in every department of literature, in every branch of art, in every scientific pursuit, are now called into vigorous and united action; and it may indeed be truly said, that we live in an era when the youth of our country cannot fail to meet, in all directions, with advocates as sincere as they are disinterested, for their intellectual progress, their moral advancement, and for the grand result of these-their future happiness. Some are labouring, with well-directed zeal, to establish literary and scientific institutions; others are cheerfully becoming the indefatigable instructors of imperfectly educated adults; and many, with an ardour and earnestness of purpose in the highest degree creditable to them as men of science and as citizens of the world, are unfolding the treasures of their well-stored minds to delighted audiences in the lecture-room. It is evident that in a publication of this varied character, it would be absurd to lay claim to any great merit on the score of originality; for, although I have not unfrequently ventured to deviate from the beaten path, under an idea that certain subjects might be rendered more inviting to the desultory reader, without detracting aught from their real value, I believe that, in such instances, no unwarrantable liberties have been taken, no levity indulged in where the subject required a becoming gravity, and no attempt made to render an article merely amusing, which ought to be strictly didactic or logically exact. In short, it has been my constant aim, as far as the limits of this publication would permit, to collect into different foci the result of the observations I have made, and to reflect the scintillations of light from every quarter within the compass of my circumscribed vision. It may, at first sight, appear that a great disparity exists between the length of the different articles. It must be remembered, however, that many are merely definitions of technical terms, which could be better and more clearly expressed in a brief sentence or two, than in half a column. The magnitude or intricacy of others demanded a comparatively long discussion; and there few which, either from their novelty or their present popularity, would be considered as too slightly noticed, if the same process of condensation had been used in regard to them, as was applied to others, of equal importance perhaps, but more generally known, or better understood. are not I am well aware how natural it is for a person who is engaged in any particular study, or who has a predilection for some given topic, to be desirous of making himself as fully acquainted with it as possible, and to feel, perhaps, a degree of disappointment, where another person, with different views and pursuits, would be abundantly satisfied; but the candid reader, I am persuaded, will grant, that a complete system of any science can hardly be expected in a work whose highest excellence must, after all, be a judicious brevity; and that if principles be clearly stated, they will often suffice till the details can be sought in works especially adapted for their elucidation. My great object has been to produce a book that should meet the wants and |