' i24 ESSAYS AND OBSERVATIONS 



alkali and the vitriolic acid, or a vitriolated 

 tartar, and digeft the mixture with a ftrong 

 heat, the vitriolic acid does not remain with 

 the alkali, but is joined to the quick-filver 

 which it attrads more weakly, compofing 

 with it a tuibith mineral j while the al- 

 kali is joined to the nitrous acid which it 

 likeways attracls more weakly than it 

 does the vitriolic, and is converted into falt- 

 petre. 



. From fome of the above experiments, 

 it appears, that a few alterations may be 

 made in the column of acids in Mr. Geoffreys 

 table of elective attradions, and that a new 

 column may be added to that table, ac- 

 cording to the following fcheme, where 

 the alkaline fubftances are all confidered as 

 in their pure ftate and free of fixed air. 



Acids. Fixed air. 



Fixed alkali, Calcarious ea; th. 



Calcarious earth. Fixed alkali. 



Volatile alkali and magnefia, Magnefia. 



****** Volatile alkali. 



* * « * 



At 



