[ .98 ] 



jdly, In its fimply efflorefced ftatc the quantities are variable 

 according to the more or lefs perfed efflorefcence, the ftate and 

 temperature of the air. 



3dly, loo ^zris /oda fully aerated but thoroughly deficcated in a heat 

 fomewhat bflow ignition contains 59,86 alkali or mere foda, and 

 40,05 of fixed air per cent, or nearly 60 of alkali, and 40 of fixed 

 air. In the experiments in my former paper the foda was heated 

 to ignition, and thus part of the fixed air was probably expelled, 

 for I found only 36 per cent, of fixed air. 



Of Glauber.* 



By my determinations, 100 parts of foda (that is, mere foda, dry 

 and free from fixed air) are faturated by 127,68 of real vitriolic acid. 

 And 100 parts of real vitriolic acid are faturated by 78,32 of foda. 

 Hence if Glauber contained no leater, 100 parts of it would contain 

 43 92 of foda and 56,08 of real vitriolic acid, or nearly \^foda and 

 ^d real acid ; and this is the fiate of glauber thoroughly deficcated. 



Bdt cryflalUzed Glauber contains a large proportion of water, 

 for ICO parts of it lofe 58 by a heat fomewhat below ignition, 

 therefore 42 parts only remain which contain alkali and acid in 

 the proportion above mentioned of 44 to 56, that is, 18,48 of 

 alkali and 23,52 of acid. 



• This fait being long known by the name of Glauber's fait, I {hall /imply call 

 Glauber, this being fliorter, and ftrving as a memorial of the anticnt denomination. 

 It claims by the fame (but a much elder) title, as Scheelittm and ^Fitheritt. 



