IX 



PACK 



3. That there are active principles in the universe that 



produce motion . .58 



4, 5, 6, 7. The ancients' opinions on this subject 58 59 

 8. The ancients' sentiments respecting generation GO 



CHAP. IX. 



Of Thunder and Earthquakes.; of the Virtues of .the 

 Magnet ;. of the Elling and Flowing of the Sea y 

 and of the Source of Rivers, 



* 1. The introduction . . 61 



2. The moderns divide in their ppinions concerning 



the cause of thunder . ib.. 



3, 4, 5. The ancients' sentiments on what occasions 

 thunder . . 62 



6. Th moderns' account of the cause Of earthquakes 63 



7, 8, Aristotle and Seneca's sentiments on earthquakes ib. 

 9. The moderns assert, that the sun and moon act re- 

 ciprocally in causing the ebbing and flowing of the 



sea . . .64 



10. Pliny's account exactly agrees with this . ib. 



11. The moderns' account of the wonderful properties 



of the loadstone . . . 6.5 



12. The ancients clearly knew the virtues of the load- 



stone . . ib. 



13. Modern naturalists are divided in their opinions as to 



electric matter . $Q 



H That rivejs return from the sea to their, sources by 



subterraneous passages , 0; 



