ART. XIII. Institutes of Natural Philosophy, Theoretical and Experimental. By William Enfield, LL.D. 2d Edition, with Corrections and considerable Additions, &c. &c. 4to. pp. 450. and 11 Plates. Il. Is. Boards. Johnson. 1799. ΤΗ HE original impression of this work was reviewed by us in the year 1786 (vol. lxxiv. p. 138.)-the present is augmented by several new propositions, relations of experiments, &c. and by an introduction to the first principles of chemistry. Our remarks on the first edition were very few, because we regarded the volume not so much as containing original matter, as being a compilation of the useful and less abstruse parts of philosophy, arranged with considerable method, and discussed in a plain and perspicuous manner. This opinion of its merits continues nearly the same; and as we did not formerly withhold our criticism from motives of delicacy and regard to living reputation, so neither do we now restrain or soften it from respect to deceased worth worth to which we would here and at all times bear ample testimony. As, however, we decline entering into a particular examination of the propositions, &c. our observations will relate to the general character of the publication; and our criticisms, which will be neither minute nor numerous, we trust will be temperate: severe they could not be, except, resolved on dissatisfaction, we had required in the performance more than its author intended to introduce, or, making the demand of ignorance, we had asked for an union of inconsistent excellences. Although the intention of Dr. Enfield might not be, as he expressed himself in his preface, to open a bye path to philosophy, yet his work is evidently calculated rather to recommend and insinuate truth by illustrations and examples, than to place it before the mind stript of all blandishments, such as it must appear according to the strict rules of severe reasoning. It is not indeed to be dissembled that Dr. E. was not eminently qualified to sound the depths of science, and to unravel its most perplexed parts. The variety of the objects of his pursuit dissipated his attention; the knowlege which he possessed was extensive and multifarious; and therefore the laws, which seem to confine within certain bounds all intellectual exertion and attainments, forbad that this knowlege should be in every instance exact and profound. Let it not be understood as our opinion, that there is an antecedent reason why the same individual should not possess at once accuracy and extent of information. Examples might be brought to controvert such an idea: but, looking to the common lot of humanity, we may justly treat universality of talents and acquirements as a chi mera engendered in the warm imagination of youth, and fostered by the vanity of sciolists. Whoever pursues knowlege, let his ambition be insatiate: but let his steps be uniformly and steadily directed towards the same point; cautious that his efforts are not diverted by the solicitations of extraneous objects, and dissipated by their frequency: otherwise, he must expect his moments of disappointment; and he will find, after fruitless trials, that a man who ranges extensively will want time to investigate closely, and to search deeply. These considerations will not perhaps appear. irrelevant : they may enable us to form a just estimate of the merit of the author of the present Institutes, may propitiate the severe critic, and may incline him to forgive partial inaccuracies in a book, when he looks to the sum of knowlege which its author possessed. They may also, perhaps, for a moment, restrain the triumphant sarcasms of that tribe of puny and indolent witlings who have never felt the toil of thought, yet pronounce their opinions with confidence, and, because they can censure an author, fancy themselves superior to him; if the work be familiar and illustrative, they complain that it is superficial; if deep, dull; if systematic, tediously formal. Should one of these critics ask, purposely involving a condemnation in his question, what are the original inventions in the present Institutes, he may be told without hesitation that there are none: that the aim of the author was to treat known truths with method and perspicuity, to touch them mellao lepore; to disentangle that which was intricate, to familiarize that which was abstruse, and to reduce high matters to the level of ordinary capacity. If his book teems not with new ideas and discoveries, there are nevertheless in it (to use the words of a great writer,)" multa admista ex intimâ philosophiâ, multa dicta dialecticè, quæ quo facilius minus docti intelli gerent, jucunditate quadam ad legendum invitati." Criticism allows no work to be perfect: the faults of the présent are either to be attributed to the plan on which it is written, or are to be derived from the turn of the author's mind, and the nature of his attainments. The performance was intended as a popular one; and what is popular must to a certain extent be vague, what is familiar will be deficient in philosophic precision, and what is illustrative will want generafity. Dr.Enfield was averse from deep disquisitions and metaphysical refinements; he is found, therefore, frequently inclining *In the first Scholium, the author expresses his dislike of what he calls metaphysical refinements; and his reasonings on the Dd 4 divisibility of ing to lax reasoning, and insisting on merely verbal proposi tions. He was fond of what are called obvious and sensible truths; he did not, therefore, give to the principles of science their due exactness and generality. He feared lest the reader 'should not understand him; and therefore he sometimes props on Induction and Examples, that which ought to have been established on the firm basis of mathematical demonstration. We have endeavoured to place in a fair light the merits of this work with the imperfections which it possesses, it yet has a strong claim on public notice; if it be not faultless, it is far above mediocrity. To the present editor some notice is due. The augmentations and additions which he has given to the work may be inferred from his Advertisement: In laying before the public a new edition of "The Institutes of Natural Philosophy, by the late Dr. Enfield," the Editor feels it incumbent on him to assure the Reader, that he has endeavoured, as far as was consistent with an elementary book, to avail himself of those advantages which the publication of new discoveries, and new works in science has afforded him; and although the limits of an advertisement will not allow him to particularize all the additions that will be found interwoven with the various parts of the volume, yet it may be expected that, in this place, some notice should be taken of the most material of them; and it is presumed that the following account will be deemed sufficient for the purpose. In the first book, the propositions on the divisibility of matter, and the attraction of cohesion, are more fully discussed, and a very useful corollary is drawn from that on the attraction of capillary tubes. To the first and third propositions of the second book, considerable additions are subjoined; and in the second chapter is inserted a new proposition, from which, in conjunction with others, are deduced many corollaries and scholiums, connected with the remaining parts of the book t. Several examples are also given in the two first sections of the fifth chapter, which will be found useful to the young student as illustrative of the theory of falling bodies. In the third book is given, independently of the additions noticed in the margin, an important proposition on the specific gravities of bodies, with which are connected examples, and a table of the comparative weights of many of the most useful substances in nature. of matter, which follow, are disastrous consequences of this dis like. We wish that the Editor, instead of adding to what Dr. E. had done on this subject, had expunged all the proofs of the infinite divisibility of matter. * In page 369, there appears to be an addition, + See Prop. A, (p. 14.) and Cors. Schols. &c. to Prop. 14, 17, 74, 26, 28, 30, 31, 36, 44, 46, 49, 52, 53, 54, 57, and 58.' See additions to Prop. 3, 6, 12, 13, 18, A, (p. 103,) 50, and 55.3 Descriptions Descriptions, accompanied with figures, are likewise given of the Pyrometer, Air-pump, Barometer, with its application to the measur ing of altitudes, &c. Fahrenheit's Thermometer, with a Table of Heat; different kinds of Hygrometers, the Steam-engine, and the Hydrometer. The principal additions to the book of Optics, will be found connected with the propositions mentioned below ; in the course of which are introduced, Mr. Delaval's Theory of Colours; brief accounts of Dr. Blair's achromatic Lenses, and Dr. Herschel's grand Telescope. On the subject of Astronomy, are arranged under the different articles, several useful Tables, and the important discoveries of the illustrious Dr. Herschel, which have been carefully selected from the last twenty volumes of the Philosophical Transactions. The reference in the margint, will direct the reader to those propositions to which the most material additions are subjoined. Some valuable treatises on Magnetism and Electricity, particularly those of Mr. Cavallo, having appeared since the original publica tion of this volume, it was thought necessary very considerably to enlarge this part of the work; and it is hoped that the principal diecoveries in these branches of science will now be found under their respective heads. By the suggestion of a friend, on whose judgment the public has long placed great confidence, it has been deemed pro per that the first principles of Chemistry should for.n a part of the present volume; and although we have chiefly confined ourselves to the interesting discoveries of the philosophers Black, Priestley, and Lavoisier, on Heat and the Factitious Airs, it is nevertheless presumed, that enough has been said on these subjects to render the doctrines and introductory practice to modern chemistry perfectly intelligible to any person who may be desirous of farther prosecuting the study of this amusing and useful science. The Reader ought to be apprized, that besides additions to the old plates, two new ones are now given :-one, as already noticed, accompanying descriptions of several pneumatic and hydraulic machines, and the other containing figures relating to subjects in magnetism, electricity, and chemistry. It is hoped that the augmentations to the volume, although they compose about one-third of the whole work, will be found such as ought at this period, to be comprehended in an elementary book of science; and that the speculations of Dr. Herschel, towards the end of the astronomical part, will not be considered as an exception: they are at least the speculations of a great mind, and capable of exciting, in every well-disposed heart, emotions of interest and exquisite pleasure, inasmuch as they lead to the grandest and most sublime notions of the great Author of the universe. *See Prop. 5, 13, 22, A, (p. 157,) 42, B, (166,) 61, 62, 66, 68, 69, 76, D, (p. 188,) 94, 122, 128, 144, and 145." +See Def. 1, 12. Prop. 8, 16, 20, 32, 35, 39, 51, 57, 72. 78, 79, 83, 109, 116, 117, 118, 119, 120, 123, 136, 167, 168, 177, 179, A, B, (p. 346-7,) 182, 183.' • The The Editor will only add, that in the additions to this work, he has uniformly aimed at conciseness; and he will consider his exertions well rewarded, if it be found, by a candid and discerning public, that he has not sacrificed perspicuity to brevity, and that he has not omitted, within his prescribed limits, any material article that might serve to render the original work, in its present enlarged state, generally acceptable and useful.' The reader will find an account of three volumes of sermons by the late amiable Dr. Enfield, in our Review for September last, p. 67. אן ART. XIV. Observations on the pernicious Consequences of Forestalling, An abridgment of this work is published by the author him. self; price 2s. obtain |
