Aqueous Solutions of Acids and Alkalies. 303 



The opinion entertained by Dalton, that anhydrous salts 

 dissolve in water without adding to its bulk, is singularly in- 

 applicable to sulphuric acid. Half an atom of water, mea- 

 suring 8 - 035 scptems, saturated with SO 3 , so as to form the 

 fuming acid of 2381°, acquires the volume of 41*999 septems, 

 or 1000 septems of water produce 5227 septems of fuming 

 acid. Thus an anhydrous substance can increase the volume 

 of its solvent water from 8 to 42, or from 1 to 5\, the tempe- 

 rature remaining constant. I shall show, in treating of soda, 

 a result entirely different from this, and yet equally at vari- 

 ance with the hypothesis of Dalton. 



The hydrate of sulphuric acid that distils without change 

 in composition is the protohydrate, SO 3 + H 2 0. Hence the 

 fuming acid, SO 3 , H 2 + SO 3 , cannot be prepared by the 

 concentration of dilute acids. 







Table IV. — Muriatic Acid. 

 H 2 CF=455'13 grs. Temperature 62° F. 



