COGITATIONES DE NATURA RERUM. 223 



aiunt ut quod fortius sit impellat, debilius cedat ; earn 

 cessionem sive fugam, si minor adhibeatur vis, non 

 ultra durare quam prima impulsio continuetur ; ut in 

 protrusione ; si autem major, etiam remote corpora im- 

 pellente ad tempus vigere, donee sensim remittatur ; ut 

 in jactu. Atque hi rursus, alio ejusdem scholae more 

 inveterate, primordia rei eaptant, de processu et exitu 

 non solliciti ; tanquam prima quasque csetera trahant ; 

 quo fit ut immatura quadam impatientia contempla- 

 tionem abrumpant. Nam ad id quod corpora sub 

 ipsum ictum cedant, aliquid afferunt ; sed postquam 

 corpus impellens jam remotum sit, adeo ut necessi- 

 tas ilia confusionis corporum jam plane cessaverit, cur 

 postea motus continuetur, nihil dicunt, nee seipsi satis 

 capiunt. Alii autem magis diligentes l et in inquisi- 

 tione perseverantes, cum vim aeris in vends et simili- 

 bus quse vel arbores et turres dejicere possit animad- 

 vertissent, opinati sunt earn vim quae hujusmodi missilia 

 post primam impulsionem deducat et comitetur aeri 

 debere attribui, pone corpus quod movetur collecto et 

 ingruenti ; cujus impetu corpus tanquam navis in 

 gurgite aquarum vehatur. Atque hi certe rem non 

 deserunt, atque contemplationem ad exitum perdu- 

 cunt ; sed tamen a veritate aberrant. Res autem vere 

 in hunc modum se habet. Prsecipuus motus partibus 



1 See Fracastorius, De Sympath. tt Antipath. c. 4., to whom Bacon refers 

 in the Nov. Org. fn. 36., Vol. I. p. 447.] That the medium through which 

 a body is projected is the cause of its continuing to move after it has parted 

 from that which projects it, had however been taught by Aristotle. See 

 the Physics, viii. 10. ; a passage which, though the theory of projectiles 

 contained in it is altogether false, yet shows that Aristotle had formed a 

 distinct though incomplete conception of the propagation of motion through 

 any medium. Aristotle s view seems not to have been rightly understood 

 by his commentators. See Brandis s Scholia, p. 451., at bottom; and com 

 pare Cardan, De Subtil, ii., and Vanini, Dialogi, xi. 



