130 PHILOSOPHY OF 



by the volatile oils, naphtha, phosphorus, and 

 various other combustibles, which unite with 

 chlorine, when it explodes as when heated to 

 212 F. 



Euchlorine, peroxide of chlorine, and deutoxide 

 of hydrogen, also expand with explosion and evo- 

 lution of heat and light on being decomposed, 

 because the affinity of their particles for caloric is 

 diminished by reducing their size. The more 

 completely ponderable matter is divided, the less 

 power it has of concentrating, or retaining sethe- 

 real matter around its particles. Hence, the 

 quantity of caloric given out during ordinary com- 

 bustion, other things being equal, is in proportion 

 as the decomposition is complete. When coal or 

 wood is but partially decomposed, gross vapours 

 are formed, constituting smoke, the particles of 

 which are much larger than those of flame, and 

 which retain and carry off a considerable amount 

 of the caloric that is given out by radiation when 

 the combustion is perfect. 



The whole theory of combustion is founded on 

 the various degrees of force with which ponder- 

 able matter attracts t/termo tztkereal matter, under 

 different circumstances. Caloric is more con- 

 centrated around the atoms of dense, than of light 

 gases and vapours ; and greatly more so around 

 the larger compound particles of liquids and 

 solids. In short, all the absorptions of caloric 

 by which it combines with and becomes latent in 



