2 



15. Great Improvements from the Art of Chyrnistrv. 

 1^5. Discoveries concerning the Loadstone. 



17. Concerning Glass and Burning-Glasses. 



18. The Nature of ihe Air is more accurately discovered by means 



of the Barometer, the Thermometer, and the Air-Pump. 



19. Discoveries relating to \Yater. 



20. Discoveries which shew the Nature of Fire, Gunpowder, 



Aurum Fulminans, Phosphorus. 



21. Of the Earth, and the chief Systems of the Universe. 



22. Of the Sun, the Planets, and their Satellites. 



23. Of the Causes of Natural Bodies. 



24. Of Spirits and Divine Things. 



jSl 



ATURAL PHILOSOPHY treats both of 

 GOD himself, and of his creatures, visible and invisible. 

 Of these 1 purpose to speak in such a manner as to as- 

 cend from the consideration of man, through all the 

 orders of things as they are farther and farther re- 

 moved from us, to GOD the centre of all knowledge. 

 (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 Goo ; 

 practical, descends from GOD to man. 



2. The most ancient nations, the Egyptians and 

 Hebrews, in particular, philosophized much concern- 

 ing GOD, and concerning Genii, good or evil spirits, 

 of an order superior to man. What they taught con- 

 cerning 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 pos- 

 terity what they had received from their forefathers. 



3. Among the Greeks, Thales 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, lleie the foundation of natural 

 history was laid, in various observations on plants, 

 animals, and other things. And herein the endeavours 

 of A mtut'e and Thcophrastus 5 iu particular ; are to be 



