Philosopher if he is so too: but the properties of the elements are opened to us in a great measure by the experiments of Chemistry Electricity has but little to do with calculation; and the philosophy of the three kingdoms, of plants, animals, and fossils, all full of wonders, may be treated of without the formulee of Algebra.

If

Life is so short, and knowledge comes so slowly to man in this mortal state, that nothing should be represented under an obscure form, which is capable of a plain one. obscurity is an art, any man may attain to it, and may soon render unsearchable that which is not worth finding. The proper end of every instructive composition is to illuminate: and the small taper, which gives us light to read by, is preferable to the blazing meteor of the sky, which raises our astonishment, but soon leaves us in darkness. Authors in all ages have been touched with the ambition of being mysterious; as if learning grew more honourable in proportion as it is less intelligible. This sentiment is so handsomely and judiciously expressed by a writer who has fallen in my way, that I shall place his words in the margin for an admonition

to

to the learned*. Instead of making difficult what is naturally easy, it is my desire, and has been my endeavour, to invent such a method as might render easy what is naturally difficult. In the style and manner of my work, I have rather proposed Seneca and the elder Pliny as my models, than the authors of Systematical Treatises, who are perhaps too cautious of departing from the natural dryness of their method. One author indeed has of late ventured to give a more liberal and classical turn to a philosophical discourse, the subject of which is nevertheless handled with mathematical exactness t. Mathema

* Dolendum vero jure meritoque est, quod ratio humana, etiam in hoc negotio, labem illam suam primordialem, fastum atque superbiam, pro lapide offensionis et fundamento lapsus sui habeat: dum simplicitatem perosa, nihil nisi speciosa, operosa, intricata, abstrusa, affectans: notiora vero, faciliora, singularia, despiciens: perverso ordine, fastigio adnitens, vel omnino inde excutitur, atque in inane decidit; vel clausa ibi omnia atque obsignata deprehendens, et interiora penetrare impos, ex superficialibus quibusdam, crassioribus, Phænomenis, fingit sibi potentias quasdam, difficillime quidem materiales, promptissime vero immateriales; e quibus hodierni illi insiti et concreati nisus et motus, Materiæ interni, et quæcunque illos possidens atque perficiens facultas, primum locum possident. STAHL. Specim. Becher, p. 234.

+ Doctrina Sonarum, by the ingenious Mr. Hales of Dublin.

Mathematicians are wont to consider the elements so far only as they come under the idea of quantity: whereas the Science of Physics should consider them chiefly in their qualities and operations. Quantity is the body of Nature, and Quality is the soul of it. The part of Natural Philosophy which always seemed to me most useful and instructive, was the economy of the Elements, and the final causes of their effects; which, in some respects, have been admirably well treated of by Ray, Derham, Neiwentyt, and other excellent writers of that class. This sort of Philosophy may be thought less sublime, because it has less difficulty; but it may be of more general benefit than abstruse theories, which may do great honour to their authors, but lock up, even from persons of good learning, what they would be glad to partake of, according to their measure, in a more popular form.

Though I never advertised the conditions of this volume in the public papers, I

gave my friends reason to expect, from my private proposals, that it would contain a Discourse on Electricity. This I reserved for the last; that while the other papers were in the press, I might take advantage of any thing new that

that should arise from others, or occur to myself, to render it more perfect. In the mean while, the volume grew to such a size, and the other discourses took up so much more room than my calculation had allowed, (I wish I may have under-rated them in every other respect) that to keep the volume within bounds, and to the proposed price, I am obliged either to reserve that piece for the other volume, or make a treatise of it by itself. To bring it into any tolerable compass for this present publication, I must have changed its form, and abridged my materials into titles and propositions; by doing which I should have disappointed my reader, and have been unjust to myself as well as to the subject. My plan receives such confirmation from the new lights of modern electricity, that I cannot say whether I should have been bold enough to have undertaken any part of it without that encouragement. This volume, however, contains nine separate Discourses, the number which my proposals promised: and as these carry us through the elements of fire, air, earth and water, the volume is so far a complete work by itself. Instead of a few paragraphs, which were all I intended to select on the philosophy of musical

1

musical sounds, and to introduce them into the Discourse upon Air; I have published the chief of my speculations on that subject, and made a separate discourse of it. I should have been tempted to add some farther considerations, had I seen the Discourse of the Spaniard, Feyjoo, upon Music, before my own was printed: but now I must refer the musical reader to it, not as a philosophical, but a sentimental piece. Had I been apprized of it in time, I would have mentioned the great Lord Keeper Guildford, as the father of Musical Philosophy in this country; who first started it in our Royal Society, and was followed by Matthews, Hook, Wallis, and Holder. Essay on Music, which in those earlier days had great merit; and was himself a very skilful composer*. I might also have descended to a particular inquiry into the effects of music upon the passions, under the title of Pathology; and have shewn how the larger intervals elevate and expand the mind, while the lesser depress and contract it; on which there is much to be said; and the consideration of it, if I could be so happy as to represent

He printed a Philosophical

* See Roger North's Life of the Lord Keeper Guildford,

p. 296.