5 a 'Jr7>Mf//**/BODIES. Chap; 7; 



fibletnat ah exceeding rarified fire, mtycaufc a farre lefTc im. 

 prefTion of heat then we are able to feel. Confider how if you 

 fet pure fpirit of wine on fire, ami fo convert it into a&uall 

 flame; yet it will not burn, nor fcarce warm your hand : and 

 then ca# you erpefr. that the light of a candle which fillcth a 

 great room, fhould burn or warm you as far as itfhincth ? 



If you would exaftly know what degree of heat, and 

 power of burning that light hath, which (for example J ill i- 

 iie:h upon the wall in a great chamber , in the middeft where- 

 of there frandeth a candle j do but calculate what overpro- 

 porticn of quamitie all the light in the whole room bcarcch 

 to the quantity of the little flame at the top of the candle, and 

 thar is the ovcrproportion of the force of burning which Is in 

 the candle, to the force of burning which is in fo much light 

 at the wall as in extcnfion is equal! to the flame of the can* 

 die. Which when you have considered, you will not quarrell 

 at its not warming you at that diffance ; although you grant 

 it to be fire, ftreamingout from the flame as from the fpring 

 that feedeth it , and extremely dilated ( according to the na- 

 ture of fire, when it is at liberty) by going fb farre, without 

 any other groflc body to imprilbn or clog it. 



It is manifeft , that this rule of examining the proportion 

 of burning in fo much of the light as the flame is, ( by calcu- 

 lating the proportion of the quantity or extenfionof all the 

 light in the room to the extenfion of the flame of the candle, 

 and then comparing the flame of the candle to a part of liglu 

 equall in extenfion unto it) is a good and infallible one, if 

 we abftra&from accidentall inequalities : Cncc both the light 

 and the flame arc in a perpetuall flux ; and all the light was 

 iirft in the flame, which is the fpringfrom whence it continu- 

 ally floweth. As in a river wherein evry part runneth 

 with a fettled ftrcam; though one place be ftraightcr, and 

 another broader ; yet of neceffitic , fince all the water that 

 is in the broad place came out of the narrow, it muft follow 

 that in equall portions of time, there is no more water where 

 it hath the liberty of a large channell, then where the banks 

 prefle it into a narrower bed , fb that there be no inequalities in 

 the bottome. 



In like manner, if in a large ftoye a bafifl of water be con- 

 verted 



