243 ON A NATURAL SYSTEM 



tircly to have difappcared. In this Hate of e- 

 quilibrium, then, it becomes a matter of indiffe- 

 rence whether the preference be given to the 

 acid or the alkali. To the latter however I 

 ihould rather incline, as the moll convenient ; 

 but I would not violently oppofe any one who 

 might think proper to refer them to the acid, or to 

 a diftincl genus. Quantity may in this cafe, in 

 fame mcafure, aflifl our determination; but not 

 without irregularity : For, as the pure fixed al- 

 kali is Saturated with a weight of acid lefs than its 

 own; fo, on the oilier hand, the volatile alkali 

 requires the acid to be heavier than itlelf. 



5 LXIX. Kttxcd Neutral Sahr* 



IT may happen, that the fame acid is partly 

 faturated with one alkali, partly with another; 

 and yet nevcrthcleft, thele three arc foilrongly 

 united by crytlulli/.arion, as to conilitute but 

 one peculiar fait. The fult of Seignette afFordsan 

 inilance of this fpccics of compolition ; the 

 cream pf tartar like wife faturated with volatile 

 alkali. That the fume alkali may be combined 

 with two acids, the union of cream of tartar 

 with the acid of borax fullicicntly dcmonflrates. 

 In the foflll kingdom, indeed, we find none of 

 thefe triple fults ; but they inform us what may 

 be done towards eflublilhing a general arrange- 



icut. The fait of Scignette, with the arid cf 



buro: 



