Fixed Vegetable Alkali, ^c, 69 



flammable part of the plant, with the native acid, 

 t-he aqi;eous part being difTipated in the procefs. 



On the other hand, it was by a few perfons 

 conjedurcd, that the alkali exifts in vegetables 

 perfedly formed previoufly to the combuftioni 

 and that the operation of the fire is nothing more, 

 than a perfed feparation and diffipation of the 

 other principles, by which it was entangled and 

 concealed. 



In confirmation of this latter opinion, it was 

 alledged, thacMeflis. Eeaume^ ^nd BouUuCy-f &cc. 

 had extraded nitre, and other falts, of which this 

 alkali is the bafe, from feveral plants by infufion 

 and deco(flioti, without incineration. In anfwer 

 to thefe obfervations it was advanced that the 

 nitre, &c. thus detected, muft be confidered as 

 foreign, adventitious, and not eflential to the 

 plant, becaufe from the fame fpecies the quan- 

 tity obtained at difi'erent times is extremely 

 variable. Its exiftence, therefore, at all in plants, 

 mufl: be afcribed to fome peculiar circumftances 

 of culture and foil j and in proof of this, it was 

 remarked, that it frequently happens, that the 

 fame plants which contain much nitre, when 

 thefe two circumftances favour its introdu6tion, 

 contain none at all in contrary circumftances. 



• Dift. of Chemiftry, Article, Alkali Fixed Vegetable, 

 f Encycloped. Art. Nitre and Mem. del Acad. de$ 

 Sciences. i73i» 



F 3 Of 



