164 NOVUM ORGANUM. 



Ad dccimam quartam. 



20. Huic non subjungitur neyativa. Nihil onim re- 

 ])eritur apud nos sive tangibile, sive spirituale* &quot;, quod 

 admotum igni non excipiat calorem. In eo tamcn 

 differunt, quod alia excipiant calorem citius, ut aer, 

 oleum, et aqua ; alia tardius, ut lapis et metalla. Ve- 

 rum hoc pertinet ad Talitlam araduitm. 



Ad dccimam &amp;lt;j unit am. 



21. Huic instantiate non subjungitur iiegatim alia, 

 quam ut bene notetur, non excitari scintillas ex silice 

 et chalybe, ant alia aliqua substantia dura, nisi ubi ex- 

 cutiuutur niiimtiiL aliquaj ex ipsa substantia lapidis vcl 

 metalli: ne&amp;lt;)ue aereni attrition unquam per se gencrare 

 scintillas, ut vulgo putant 8 : qnin et ipsa- ilia; scintilla 

 &amp;lt;&amp;gt;x pondere corporis igniti magis vergunt deorsnm quam 

 sursuin, et in extinctione rcdeunt in quandam fuligi- 

 nem corpoream. 



Ad dccimam xc.t taw. 



22. Existimamus liuic instantia&amp;gt; non subjungi ncqa- 

 tivam. Nullum enim invenitur apud nos corpus tan- 

 gibile, quod non ex attritions manifesto calcscat (i! * ; 

 adeo ut veteres somniarent, non inesse cu-lestibus aliam 

 vim aut virtutem calefaciendi, nisi ex attritione aeris 

 per rotationem ra]idam et incitatam. A r cruin in hoc 



1:7 An old Scholastic division. By so seem colder to the touch. 

 &quot; spirituale&quot; Bacon probably here ^ Air under compression does 



means such things as Gases. His emit sparks of sufficient intensity 



view of the relative speed of differ- to ignite German tinder, 

 ent substances in acquiring heat is J Friction is one of the most 



all wrong. Air (as it is so bad a important sources of Heat ; as 



conductor) is very slow: Metals are Count Rumford s experiments have 



particularly rapid ; but because of proved that an unlimited supply of 



the far greater number of their par- Heat can be obtained by it without 



ticks, they do not shew it so quick- diminishing the quantity of the ma- 



ly; and for the same reason they terials. 

 carry off Heat far more rapidly, and 



