33 



usque ceulra miIis et planelamm, sine virlutis diminutione; 

 quaeque agil non pro quantitale supcrficierum parlicularutn, in 

 qtias agil (ul solent causae mechanicac), sed pro quantitale ma- 

 icriae solidae. — Rationem harum gravitatis proprietatum ex 

 phaenomcnis nondum potui deducere et hypotheses nun lingo. 

 Salis est quod gravitas revera existat et agat secundum leges a 

 nobis expositas. 9ienUon, Principia Phil. nat. p. 676. — 

 l'o teil us that evcry species of things is endow'd wilh an occult 

 speciGck qualily by which it acts and produces manifest effects, 

 is lo teil us nothing: but lo dcrivc two or thrcc general prin- 

 ciples of motion from phaenomena, and afterwards to teil us how 

 the propcrties and actions of all corporeal things follow from 

 those manifest principles, would bc a very great Step in Philo- 

 sophy, though the causes of those principles were not yet dis- 

 covered : and therefore I scruple not to propose the principles of 

 motion and leave their causes lo be found out. Newton. 

 Opticks p. 377. ^rö^er, Query 31 p. 351, tydjjt e$: «odies 

 acl one upon anolher by the attraction of gravily, magnetism 

 and eicclricily, and it is not improbable that there may be more 

 altractive powers than these. How these attraclions may be per- 

 formed, 1 do not here consider. What I call attraction, may be 

 performed by impulse or by some other mcans unknown to me. 

 I use that word here lo signify only in general any force by which 

 bodies tend towards one anolher, whatsoever be the cause. 



41 (©. 23.) I suppose the rarer aclher within bodies and 

 the denser without them. Oper um New ton i Tomus IV. (ed. 

 1782 ©am. jjorälep) p. 386, mit Knwenbuna auf bte Srflärung 

 ber von ©rimalbi entbeeften 2>iffractton ober 2t(btbeugung. 3Tm 

 ®d)luffe be$ Sörtefeö von Newton an Robert 53ople vom $ebr. 1678 

 p. 394 bftjjt ei: I shall sei down one conjeeture more which came 



inlo my miud: it is about the cause of gravily <Hud) bte 



(£orrefponbenj mit ölbenburg vom 2>ecember 1675 beroetft, bafi 

 Der große Wann bamald ben Sterbet: jjppotbefen nidjt abgeneigt 

 war. 9lad) biefen follte ber ©toj» be$ materiellen Siebtel ben 

 tfetber in ©cbivingung fefeen; tie ©cbwingungen beä Sfetberä allein, 

 iveldjer ^ertvanbrfebaft mit einem Nerven --^luibum t>at, erjeugten 

 niebt ba* 2idjt. @. über ben ©treit mit Jpoofe £ orale» T. IV. 

 p. 378-380. 



?1 ». -Viiml-olH, Äi'diu'« III. 3 



