[ 247 ] 



SeBlon id. 



Common Salt. 



It has been feen in my laft paper that 30,05 grains of mer^ 

 foda were faturated by 129 grains of muriatic acid or fp. of fait, 

 whofe fp. gravity in the temperature of 60*" was 1,1355 i ^^i* ^1 

 the table contains about 17,5 real acid percent, confequently 

 129 grains of it contained 22,07 grains real acid, if therefore the 

 neutral fait here formed contained nothing elfe but mere foda 

 and real acid, its weight ftiould be 30,05 + 22,07 = 52,12. Yet 

 by the laft experiment it appeared that the weight of the- fait 

 thus formed amounted to 56,74 gr. the furplus 4,62 grains muft 

 therefore have been water, and finee 56,7+ grains of common 

 fait contain alkali, real acid and water in the above proportions, 

 100 grains of common fait (well dried and deprived of the water 

 interfperfed between its pores) muft contain 52,96 foda, 38,88 

 real acid, and 8,16 water of compofition that always accompanies 

 the acid when this fait is formed, and therefore muft in all other 

 ways of examining the compolition of this fait, have been con- 

 founded with it. In this fenfe therefore I may fay that 100 parts 

 common fait contain in round numbers $^ parts alkali and 47 of 

 acid. 



Hesce 100 parts mere foda take up 73,41 of real marine acid, 

 or 88,74 of the aqueous acid, and then afford 188,74 of common 

 fait. And 100 parts of the aqueous acid ihould take up 112,688' 



of 



