Introduction

OF THE GRADUAL IMPROVEMENT OF NATURAL PHILOSOPHY

1. NATURAL PHILOSOPHY treats both of God himself, and of his creatures, visible and invisible. Of these I purpose to speak in such a manner, as to ascend from the consideration of man, through all the orders of things, as they are farther and farther removed from us, to God the centre of all knowlege. (I mean, of visible things ;—of the invisible world we cannot know much, while we dwell in houses of clay.) Thus speculative phi­losophy ascends from man to God; practical, decends from God to man.

2. The most ancient nations, the Egyptians and Hebrews in par­ticular, philosophized much concerning God, and concerning Genii, good or evil spirits, of an order superior to man. What they taught concerning the visible world, related chiefly to its origin, the changes it was to undergo, and its final dissolution. But on all these heads they only delivered to their posterity, what they had received from their forefathers.

3. Among the Greeks, Thaics Milesius and his followers, appli­ed themselves, with great industry, to discover, with the best helps they had, the material causes, of’ natural things. They were succeeded by others, who more curiously searched into the structure of natural bodies. Here the foundation of natural history was laid, in various observations on plants, animals, and other things. And herein the endeavors of Aristotle, and Theophrastus in particular, are to be commended. Yet in other respects, Aristotle did not promote, but rather obstruct the knowlege of nature: for he made philosophy as unintelligible, by his abstract and metaphysical notions, as Plato, Pythagoras and others did, by their ideas, numbers and symbols.

4. In succeeding times, when the four Greek sects, the Pla­tonic, Peripatetic, Epicurean, and Stoic divided the western world between them, the Platonists almost confined themselves and their opinions to the subject of divinity; the Peripatetics regard­ed little but logic; the Stoics little but moral philosophy; and the Epicureans had small concern about any, being immersed in sensual pleasures: so that none of them made any considerable improvement in any branch of natural philosophy.

5. When the utter barbarism which followed, was a little dis­pelled, Aristotle began to reign. His followers (the school-men, as they were called) might have improved natural philosophy, if (like their master) they had diligently cultivated the knowledge of nature, and searched out the properties of particular things. But it was their misfortune, to neglect what was commendable in him, and to follow only what was blame-worthy; so as to obscure and pollute all philosophy, with abstract, idle, vain speculations. Yet some of them, after the Arabians had introduced the know­lege of chemistry into Europe, were wise above the age they lived in; and penetrated so far into the secret recesses of nature, as scarcely to escape the suspicion of magic. Such were Roger Bacon and Albertus Magnus.’

6. After the revival of learning, as all other branches of phi­losophy, so this in. particular received new light. And none was more serviceable herein than lord Bacon: who, well under­standing the defects of the school-philosophy, incited all lovers of natural philosophy to a diligent search into natural history. And he himself led the way, by many experiments and observa­tions. “ ‘ . .

7. After this, not single persons only, but whole societies applied themselves carefully to make experiments; that having accurately observed the structure and properties of each body, they might the more safely judge of its nature. And the advantages, which have arisen from hence, manifestly appear from the me­moirs of the royal society at London; of the academy of sciences at Paris; and those of the same kind in Germany, as well as several other parts of Europe.

8. To mention but a few of the late discoveries in each branch of natural philosophy. With regard to the structure of a human body, how many things have modern anatomists discovered, which were either little understood by the ancients, or wholly un­known to them? Such, for instance, is the circulation of the blood, discovered by Dr. William Harvey, whose “Anatomic Exercita­tions,” concerning it were first published in the year 1628. Such were the lacteal veins, discovered first in brutes, by Casper Asel­lius, of Cremona; and soon after in men. Such the thoracic duct, and receptacle of the chyle, observed first by Dr. John Pecquet, of Paris, whereby the whole course of the blood is now clearly understood.

9. Dr. Harvey improved natural philosophy, by another ‘no less eminent discovery: for he was the first of the moderns that shewed all animals to be generated from eggs. That the ancients knew and taught this, (Orpheus in particular) cannot reasonably be doubted. But as the knowledge of it was entirely lost, to revive was the same thing as to invent it. It is obvious, how great a light this pours upon that dark subject, with regard to the generation of men, as well as of other animals.

10. Another remarkable discovery in the last century, was that, of the transfusion of the blood. The blood of a young, lively, healthy animal was transfused, by means of a small, silver tube, properly adjusted into the veins of another, which was old, weak, and sickly. And the effect amazed all the beholders. When the experiment was tried before several of the royal society, a feeble, worn-out dog, ready to die with age, and hardly able to trail his legs after him, was no sooner filled with young blood, than he leaped up as from sleep, shook himself, and ran up and down, as lively and active as a puppy. In France the experiment has been made upon men, and with as surprising success. What pity, that so important an experiment should ever fall into disuse! That it is not still repeated upon proper occasions ! Especially where all other means fail.

11. It cannot be denied, that physicians have signally improv­ed this branch of philosophy, as they have continual opportunities of making new discoveries in the human body. In diseases them­selves, the wonderful wisdom of the Author of nature appears: and by means of them many hidden recesses of the human frame are unexpectedly discovered. The powers of medicine also variously exerting themselves, lay open many secrets of nature.

12. And how many things in all bodies, as well as in the human, which eluded all the art and industry of the ancients, have the moderns discovered by the help of microscopes? Although these are not properly a modern invention: it being certain, some­thing of this kind was in use many hundred years ago. There are several works of great antiquity still extant; the beauties of which cannot even be discerned, much less could they have been wrought, by the finest naked eye, which ever was in the world. Such is that seal, now in the cabinet of the king of France, allowed to be at least fifteen hundred years old, six-tenths of an inch long, and four broad, which to the naked eye presents only a confused groupe, but surveyed with a microscope, distinctly exhibits trees, a river, a boat, and sixteen or seventeen persons.

13. Now whatever assists us in searching out the structure of a human body, equally helps us to find out the nature and proper­ties of other animals. Hence in these likewise we have received great light, from anatomical and microscopical observations. Those especially who have bestowed their whole time and thoughts on one kind of animals (as Dr. ‘Willoughby, on fishes, Dr. Swammerdam, of Amsterdam, on insects), have illustrated to a surprising degree, the subjects on which they wrote.

14. Many have diligently searched into the nature of plants; particularly Mr. Ray, who has not only ranged them in a new method, but also wrote an elaborate history of them. Others have described, with equal diligence, either plants in general, or those of a particular country. And others have shewn die like industry in finding out and explaining the nature of stones, metals, minerals, and other fossils.

15. Nor is it strange that the moderns have penetrated farther into the recesses of nature than the ancients, considering the advantages they have received, from the art of’ chemistry. Not that this is an invention of later ages: it was in some measure known long ago. But as this art has been cultivated in our age, with far greater accuracy than ever, so by this means many pro­perties of’ natural bodies have been discovered; of fossils in particular.

16. But none of these have so much engaged the study of the learned, or so well deserved it, as the load-stone. Its attractive force was known to the ancients, and the origin of that discovery is recorded by Pliny. But it does not appear that they knew of its pointing to the pole, or of the use of the compass. This (the compass) was invented by John Goia, in the year 1300. But it has since been observed, that the magnetic needle seldom points ex­actly to the pole; but varies from it some degrees to the east or west, in a fixt and regular order. .

17. Nearly related to the nature of fossils is glass, which was well known to the ancients, being mentioned by Plutarch and Lucian among the Greeks, by Lucretius, Pliny, and others among the Latins. Yet the art of making glass has been since their times abundantly improved. One branch of this is, the art of making burning-glasses, which are now brought to so great perfection, as either to melt or reduce to ashes the most solid bodies, in a few moments. If these were known to the ancients at all (which may reasonably be doubted), yet the art was wholly lost for many ages, and not recovered till of late years.

18. Later ages have likewise made many discoveries with regard to earth, water, fire, and air: the last of which, AIR, though it he of so fine a texture as to be wholly invisible, yet producing such amazing effects, has excited the most diligent enquiries of the curious. Nor does any part of philosophy afford a wider field for experiments and discoveries. The weight of it we can ascer­tain by that curious instrument, the barometer, invented by Torri­cellius; the degrees of heat and cold, by the thermometer. By the air-pump (invented by Otto Gucrick, mayor of Magdeburg) the air is drawn out of any bodies, or more largely thrown into them. And hereby many effects are produced, which deserve our diligent consideration.

19. With regard to WATER, the discoveries of later times are numerous and important. Such are the (living-bell, invented by George Sinclair; the diving-machine of Alphonso Borelli, a kind of boat, which is so contrived as to be navigated under water; and the art of making salt-water fresh, which is now done with little expense, so far that the saitness is taken away, and it is fit for almost all uses.

20. The nature and properties of FIRE also have been accu­rately traced in late ages: for which new occasion was given by the invention of gun-powder, by Berthold Schwartz, in the four­teenth century. Aurum fulminans, a yet later invention, goes off with a louder explosion than gun-powder. Other bodies there are, which do not burn, yet emit light. Such is the Bononian stone, which, placed in the dark, diffuses light like a burning coal. It is well known that the preparation called phosphorus, has the same property.

21. Various theories of the EARTH have lately appeared. But they are no more than ingenious conjectures. The same may be said of the systems of the universe, a few particulars excepted.

The Ptolemaic system, which supposes the earth to be the centre of the universe, is now deservedly exploded: since Copernicus has revived that of Pythagoras, which was probably received by most of the ancients. Tycho Brahe’s, which jumbles both together, is too complex and intricate, and contrary to that beautiful simplicity, conspicuous in all the works of nature.

22. The telescope (invented by Galileo) has discovered many stars unknown to the ancients, together with the nature and mo­tion of the planets, both primary and secondary. By this also have been discovered the spots of the sun, the inequality of the surface of the moon, the nature of the galaxy, or milky-way, and many other particulars relating to the heavens.

23. With regard to body in general, it is commonly supposed, that our age has a vast advantage over antiquity, by having found out new principles and new hypotheses, whereby we can accQuflt for all the secrets of nature. But this will bear a dispute. For beside that the chief of our hypotheses, are not new, but known long ago, the learned have hitherto very little profited by all their hypotheses. And in truth, all their disquisitions touching the causes of natural bodies, terminate in mere conjectures: one whereof is often more probable than another; but none admits of any solid proof.

24. What remains of natural philosophy, is, the doctrine con­cerning God and spirits. But in the tracing of this we can nei­ther depend upon reason nor experiment. Whatsoever men know or can know concerning them, must be drawn from the oracles of God. Here therefore we are to look for no new improvements; but to stand in the good old paths : to content ourselves with what God has been pleased to reveal; with the faith once delivered to the saints."