"It being only an explication of qualities which you desire of me, I shall set down my appreliensions in the form of suppositions, as follows: And first, I suppose, that there is diffused through all places an ethereal substance, capable of contraction and dilatation, strongly elastic, and, in a word, much like air in all respects, but far more subtile.

"2. I suppose this ether pervades all gross bodies, but yet so as to stand rarer in their pores than in free spaces, and so much the rarer, as their pores are less. And this I suppose (with others) to be the cause why light incident on those bodies is refracted towards the perpendicular; why to well polished metals cohere in a receiver exhausted of air; why stands sometimes up to the top of a glass pipe, though much higher than 30 inches: and one of the main causes, why the parts of all bodies cohere; also the cause of filtration, and of the rising of water in small glass pipes above the surface of the stagnating water they are dipped into: for I suspect the ether may stand rarer, not only in the insensible pores of bodies, but even in the very sensible cavities of those pipes. And the same principle may cause menstruums to pervade with violence the pores of the bodies they dissolve, the surrounding ether, as well as the atmosphere, pressing them together.

"I suppose the rarer ether within bodies, and the denser without them, not to be terminated in a mathematical superficies, but to grow gradually into one another; the external ether beginning to grow rarer, and the internal to grow denser, at some little distance from the superficies of the body, and running through all degrees of density in the intermediate spaces. And this may be the cause why light, in Grimaldo's experiment, passing by the edge of a knife, or other opake body, is turned aside, and as it were refracted, and by that refraction makes several colors."Boyle's Works, vol. i., p. cxii.

It would be vain to attempt to compress into a periodical article even the briefest analysis of miscellaneous works like those of Boyle, which fill six thick quarto volumes; all we undertake, therefore, is to make such observations as occur to us on the portions which have interested us most, and ask our readers, as we proceed, whether their author is not worthy of being remembered. That this is as much as we could pretend to accomplish will be readily admitted, when it is borne in mind that the tables of contents alone of the different volumes would occupy a considerable proportion of the space which we can devote to this article. We cannot make room for all the titles; we must, in general, content ourselves with those of the philosopher's most remarkable productions.

In the first volume we have his " New Experiments Physico-mechanical touching the Spring of the Air and its Effects," and a "Defence of the Doctrine touching the Spring and Weight of the Air." We have another defence of the same experiments, because their being new at the time caused them to be attacked by many. Another curious essay bearing on the same subject is that entitled "An Examen of Hobbes's Dialogus Physicus de Natura Aëris, &c., with an Appendix

touching Mr. Hobbes's Doctrine of Fluidity and Firmness." We have also "Some Specimens of an Attempt to make Chemical Experiments useful to illustrate the Notions of the Corpuscular Philosophy;" "The Sceptical Chymist; or Chymico-Physical Doubts and Paradoxes touching the Experiments whereby vulgar Spargyrists are wont to endeavor to evince their Salt, Sulphur, and Minerals to be the true Principles of Things;" Experiments and Considerations touching Colors; ""The Experimental History of Colors," &c.

These are but a few of the topics treated in the first volume, and all were new at the time; in order, therefore, to do justice to the genius of the author, we must take the latter fact into account in examining his works; that is, we must not compare them with works written more than a century later, and which embrace the results of the researches of many investigators. This would not be fair; but no comparison made by an intelligent person would derogate in the least from the credit which is justly due to Boyle for his undoubted originality and foresight, although his modesty is everywhere apparent, even in his titles. He states nothing dogmatically; on the contrary, he lays down his most important propositions as opinions which may be erroneous, rather than as facts which cannot be disputed.

The second volume opens with "Some Considerations touching the Usefulness of Experimental Philosophy.' This is followed by three essays on the same subject; then we are presented with a fourth essay, which is entitled "Digression concerning those that would exclude the Deity from intermeddling with Matter." We have similar essays on the "Usefulness of Natural Philosophy." In connection with these there are three remarkable essays on the "pathological, demeiotical, and hygienial parts of physic." More curious and interesting still are the "New Experiments and Observations touching Cold." Many who pretend to make great discoveries at the present day and speak like oracles would do well to read these essays carefully. We would particularly recommend to our boards of health such essays as that entitled a "Sceptical Consideration of the Heat of Cellars in Winter and their Coldness in Summer.

Still more philosophical is the third volume. Even at the present day, when the various subjects upon which it treats have exercised the abilities of so many learned and indefatigable investigators, all of whom have flourished

since the time of Boyle, it is instructive as well as interesting. Of this character is the essay on the origin of Forms and Idealities with which the volume opens; that on the New Experiments concerning the relation between Light and Air ; New Pneumatical Experiments about Respiration; of doing by Physical Knowledge what is wont to require Manual Skill. Each of these would well repay perusal, even in the present boasted age; and the same remark will apply still more emphatically to the author's admirable papers on the Rarification of the Air; the Pressure of heavy Solids and Fluids; the Perviousness of Glass; Experiments to make fire and flame stable and ponderable.

Of the numerous papers which we have in the fourth volume the most interesting are those on "The Growth of Metals in their Ore;" the "Mechanical origin of Heat and Cold;" "Mechanical production of Odors;" "Natural History of the Human Blood;" "Porosity of Bodies;" "Experimental History of Mineral Waters." Those who carefully examine these and are capable of forming an intelligent estimate of their character will readily admit that, had their author written nothing else, he would have been justly entitled to rank as a philosopher; nay, indeed, there is much in this volume which is singularly prophetic, clearly pointing as it does to facts and phenomena which were then entirely unknown, but which have since rendered many discoverers illustrious.

The most interesting papers in the fifth volume are those 'which discuss different kinds of motion, the causes of the insalubrity and salubrity of the air, final causes of natural things, hydrostatics applied to the materia medica, &c. The sixth volume is occupied chiefly by the author's extensive correspondence with the most eminent philosopers and scientific men of his time. Many of these letters are highly instructive; they not only show the esteem and even veneration which some of the most learned of his contemporaries had for Boyle; they also embrace scientific facts and suggestions which philosophers of the present day would have the world consider as having never been thought of anterior to their time.

That Boyle has written essays that are not of much value is very true; it is equally true that he was not always correct in his opinions, but that, on the contrary, his views were sometimes visionary. But of what philosopher cannot the same be said? Was the divine Plato himself always right? Was not even the Stagirite sometimes egregiously

wrong? Kepler, the legislator of the heavens, while developing the great Laws which have rendered him immortal, often indulged in the most puerile speculations. How much did Galileo write which he acknowledged himself was of no value, and which is sometimes reprinted in his works only because it is his? Still more emphatically may this be said of the great Newton, who left reams of paper closely written which the most enthusiastic of his admirers could not regard as possessing any intrinsic value; even so much value in any sense as would justify their publication.

It may be admitted that the essays of Boyle on medicine are rather out of place; or at least that the subject was one upon which he was not well qualified to write; and yet they contain many hints and facts which are not without value. A similar remark may be made in reference to his essays on the Origin and Virtues of Gems; the Martyrdom of Theodora and Didymus, his Discourse of Quicksilver growing hot with Gold, and two or three others on kindred subjects. Many have objected to his theological writings; his Meditations have been severally satirized by Swift ;* similar attacks have been made on other essays of his written in the same spirit. In our opinion he would have pursued a more judicious course in leaving the treatment of theological subjects to the churchmen. But if we compare his theological writings with those of Newton we shall see that his are at least as good as those of the great astronomer. If it be alleged that they have not exercised much influence, if only for the reason that most persons who study theology prefer to take up the works of professional theologians, the fact may be admitted without any prejudice to the author's fame; but if his researches in this field did not influence others, they exercised a very decided and salutary influence on himself. We have evidence of this in all his writings, for no one has done more to reconcile the teachings of science with those of religion; nor has any divine or pulpit orator made better use of Scripture than Boyle has of science as a means of inspiring suitable ideas of the Deity. A passage or two from his writings will sufficiently illustrate this.

In showing that the study of natural philosophy, far from being injurious to religion, as many pretended in his day as they do now, he says that "The consideration of the vastness, beauty, and regular motions of the heavenly bodies,

See the Dean's Meditations on a Broomstick, and the note prefixed to it, in Bohn's edition of Swift's works.

the excellent structure of animals and plants, besides a multitude of other phenomena of nature, and the subserviency of most of these to man, may justly induce him, as a rational creature, to conclude that this vast, beautiful, orderly, and, in a word, many ways admirable system of things that we call the world was framed by an author supremely powerful, wise, and good, can scarce be denied by an intelligent and unprejudiced considerer."

Need we say that no professional theologian has uttered a nobler sentiment than this, or one better calculated to do good? But Boyle has uttered better, if such be possible; he has done so in the following brief passages, although the style in which he clothes his ideas is by no means a model in its kind : "But treating elsewhere purposely of this subject, it may here suffice to say that God has couched so many things in his visible works that the clearer light a man has the more he may discover of their unobvious exquisiteness, and the more clearly and distinctly he may discern those qualities that lie more obvious. And the more wonderful things he discovers in the works of nature, the more auxiliary proofs he meets with to establish and enforce the argument drawn from the universe and its parts, to evince that there is a God; which is a proposition of that vast weight and importance that it ought to endear everything to us that is able to confirm it, and afford us new motives to acknowledge and adore the divine Author of things. To be told that the eye is the organ of sight, and that this is performed by that faculty of the mind which, from its function, is called visive, will give a man but a sorry account of the instruments and manner of vision itself, or of the knowledge of that Opificer, who, as the Scripture speaks, 'formed the eye.' And he that can take up with this easy theory of vision will not think it necessary to take the pains to dissect the eyes of animals, nor study the books of mathematicians, to understand vision; and accordingly will have but mean thoughts of the contrivance of the organ and the skill of the artificer in comparison of the ideas that will be suggested of both of them to him that, being profoundly skilled in anatomy and optics, by their help takes asunder the several coats, humors, and muscles, of which the exquisite dioptrical instrument consists; and having separately considered the figure, size, consistence, texture, diaphaneity or opacity, situation, and connection of each of them, and their coaptation in the whole eye, shall discover, by the help of the laws of optics, how admirable this little organ is fitted