C04 -W^' Delaval en the Caufe of the 



corhbiftation of fome principles, which are com- 

 mon to all thofe fubftances. 



Thefe principles are witer, and phlogifton. In 

 vegetable acids, the phlogifton corr^bined with 

 the water, is equal, in quantity, to that which con- 

 ilicutes the inflartimable part of fpirit of wine; 

 for radical, or c6ncentrated, vinegar, is totally in- 

 flammable. 



The acid (late of vegetable matters is not eiTen- 

 tial to them, nor is it requifite to their produd^ion 

 of fixed air. For, fixed air is producible from 

 plants, when they are recent; when they are in 

 avinous ftate, and afford ardent fpirits ; and alfo 

 when they are in a ftate of putrefactive fermenta- 

 tion. From whence it appears that in their acid, 

 as well as in their recent, vinous, or putrefadive 

 ftate, they yield fixed air, by means of their 

 aqueous, and phlogiftic, principles. 



All fixed air, from whatever fubjedt it is pro- 

 cured, or to whatever bodies it is transferred, con- 

 fifts, conftantly and invariably, of the fame mate- 

 rials, combined in the fame proportions : other- 

 wife it could not reftore lime, cauftic alcalies, or 

 other matters, to their original mild ftate : be- 

 caufe, thefe fubftances cannot be recompofed, but 

 by the fafne proportion of their conftituent princi- 

 ples, which they contained, before their decom- 

 pofition. 



Thus, lime cannot be reftored to the ftate of 

 jofjild calcareous earth, bjl water, or by pure de- 



phlogifticated 



