[ 248 ] 



of foda, and afford 212,688 of common fait, and 100 grains real 

 marine acid fliould take up 136,31 of foda, and afford 257,2 of 

 common fait. 



100 grains of the aqueous acid contain 15,33 of water. 



According to Wenzel 131,5 of ignited common fait contain 

 71,5 of alkali, and 60 of his ftrongeft marine acid; confequentijr 

 100 grains common fait fhould contain 54,3 of alkali, and 45,7 

 of that acid. And 100 parts mere foda fhould afford 184 nearly 

 of ignited common fait. This flatement differs very little from 

 mine, and from Weigleb's ftill lefs, for he found 100 parts 

 common fait to contain 53,5 of alkali, and 46,5 of acid, and 

 100 parts foda fhould take up 87,5 of acid, and afford 187,5 °^ 

 common fait. 



But Mr. Bergman's flatement differs widely from the fore- 

 going, both Wenzel and I have found the alkaline part to exceed 

 the acid, he on the contrary found the acid to exceed by much 

 the alkaline, for to ico parts common fait he affigns 52 of acid, 

 6 of water and only 42 of alkali. From the great refpecl I have 

 ever entertained for this excellent man, this circumftance always 

 gave me much uneafiiiefs. To inveftigate the truth by direct ex- 

 periment otherwife than was always done appeared diiHcult. I 

 therefore endeavoured to difcover it by an indircdl experiment, 

 namely, by finding how much cauRic foda might be obtained 

 from the decompofition of a given quantity of common fait this 



decompofition 



