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folution faturate when no more air was expelled) and on the other 

 hand he tells us, that the alkaline folution contained an excefs of 

 acid, and this excefs exifling in every particle of a large folution 

 muft be confiderablc. 



In the experiment related in my laft paper, I ftated that loo 

 grains of aerated vol-alkali were faturated by 246 of marine acid, 

 whofe fp. grav. was 1,1355, which appears by the firft table to 

 contain 17,5 per cent, real acid, and confequently the quantity in 

 246 grains was 43 grains; on the other hand, the vol-alkali, con- 

 taining but 43 per cent, of fixed air, contained, by my a£tual ex- 

 periments, only 19,85 grains of mere alkali, and this quantity 

 fhould take up but 30 of real marine acid. Hence in my former 

 experiments there was an excefs of 13 grains of acid, which made 

 the fp. grav. equal to that of the teft folution, and thus induced 

 me to think the quantity of fal ammoniac formed greater than it 

 really was. 



Wenzel found 168,4 grains of vol-alkali, containing 53,75 per 

 cent, of fixed air, to require 240 grains of his fp. of fait to faturate 

 them, and this quantity of his marine acid we have already feen to 

 contain 55,17 of real acid, and 168,4 of the aerated alkali contain- 

 ed, by the analogy already ftated, 41,71 of mere vol-alkali, the fum 

 of both was 96,88 ; yet having evaporated the folution to drynefs, 

 and expofing the refiduum to a heat of 212° for four hours, he 



found 



