Fixed Vegetable Alkali^ t^c, 7 \ 



Thirdly, It is produced in the putrefaiflion 

 both of animal and vegetable matters. 



In the two laft of thele cafes, we have not in- 

 deed hitherto obtained the alkali feparate, but 

 in combination \vi:h acids forming nitrous and 

 other neutral falts. 



I. To confirm the firft of the pofitions above 

 dated, it is only requifite, before this Society, to 

 obfcrve, that no vegetable fiibftances furnifh a 

 larger quantity of alkali than the extracts of 

 plants, or their native effential falts. And in 

 the common mode of preparing this alkali by 

 incineration, it has been often remarked, that 

 even when thoie vegetable fubftances, which 

 abound with acid, are burnt with a clofe fmo- 

 thering heat (as in making the alkaline fait of 

 ^achenius) the greateft part of the acid is gra- 

 dually difilpated, and very little alkali is ob- 

 tained ; whereas, by a quick open fire, the acid 

 feems to be intimately coagitated with the earthy 

 part before fuch a difiipation can take place, 

 and the produce of the alkali is vafily larger. 

 It is a common obfervation, how minute a pro- 

 portion of alkali the afhes of charcoal yield, 

 compared to that which may be obtained by 

 bur.f^.ing an equal quantity of the fame wood in 

 an open fire.* 



II. That the vegetable alkali is produced 

 copioufly in the natural procefs of vinous fer- 



* Ntumannh Chemiftry, by Leivis, Vol. II. p. 290. 



F 4 mentation* 



