565 On Cints. 



thuff expending themselves upon the surrounding objects, x 

 poa-tiou'of carbon, repelled from its connections in the wood, 

 files off in connection with a portion of atmospheric oxy- 



fen- in the form of carbonic acid air. No sooner has this 

 appcncd than the phlogiston (hydrogen) of the fuel is re- 

 pelled from its association in the tmioer, and forming i 

 new aseociation with the oxygen of the ga?eous oxide of 

 Iightj constitutes blaze; a meteor burning in an aerial form. 

 This phlogiston and oxygen, after chemical union, turn to 

 steam, aiKJ h'nally condense to oxide of phlogiston or water; 

 uhiie an additional quantity of antierouon and light are 

 ahcd around after detachment from the oxygen, which has 

 just left them tocombine with the phlogiston to form water. 

 While these changes are going on, a portion of septoii 

 (azote) sonjetimes from tlte vegetable body, but more 

 commonly from the septous (azotic) part of the atmosphere, 

 connects itself with a part of the separated phlogiston and 

 turns it to volatile alkali (ammoniac). A part of tiie oxvseu 

 alao combines with the basis;, wliatever it is, of the pvro-r 

 ligTiic acKl, and this^ by force of antierouon, is repelled 

 into gas- 



Thuy, during the time that wood, oxygenous air and 

 a.TOfic air undergo their //7/>/e decomposition, liberated lia,hf, 

 liberated antierouon, carbonic acid ^gas, flame, oxide of 

 phlogiston nr vrater, animoniacal gas and pyrolignic acid 

 gas are quicklv produced. 



JBut these are only a part of the curious products of com - 

 bastion. There are seve\\\\ Jixed substances formed whose 

 history is no less worthy of notice than that of the volatile 

 ones already enum.erated. These are contained in the caput 

 nwFtr.um, or residuary mass left on the heartli or in the 

 fireplace after incineration, and caikd " ashes." 



'i'hese ashes are a very heterogeneous collection of materials. 

 They may be properly divided into two classes, to wit, 

 those which readily dissolve in water, and such as with dif- 

 liailty incorpoi-ate with that fluid. The fbi-mer is the snl/no 

 and the latter the earthy ])art of the ashes, And both of" 

 tnem, as they most clearly do not preexist in ihe wood, are 

 pioduced by new combinations of particles during the act 

 of burning. 



Of the saline portion of wood-ashes, the predominatin» 

 mgrcdicnt is the vegetable iixed alkali or potash. When 

 recently formed, and fresh from the fire, tliis fixed salt is 

 in a cctmtic state. By exposuie to the air in a cool place 

 for some lime it attracts iixed air and becomes a carbonate 

 ef potash. Very commonly too this alkali, when exposed 



in 



