1825.J Three new Salts of ISoda. 441 



tated by muriate of barytes. The sulphate of barytes obtained, 

 after being washed, dried, and heated to redness, weighed 30*32 

 grains, equivalent to 10*278 grains of sulphuric acid. Now 

 10*278 approaches so nearly to 5*377 x 2, that we can have no 

 doubt that the salt contains 2 atoms of sulphuric acid. 



I ascertained by an experiment to be stated immediately that 

 the reason why the sulphuric acid, obtained by means of the 

 muriate of barytes, was not exactly double that contained in the 

 neutral sulphate of soda was owing to a deficiency, in all proba- 

 bility proceeding from some additional portion of water adhering 

 to the'salt analyzed ; for it is rather difficult to get the salt in 

 the proper state of dryness to fit it for analysis. 



If we consider the salt as a bisulphate, and reckon the acid 

 twice as much as was found in the neutral sulphate from 20 grs. 

 of the salt, then the constituents will be as follows : 



Sulphuric acid . 10*755 or 10*0 



Soda 4*322 4*0 



Water 4*922 4*57 



20*000 



The numbers in the second column are the equivalents for the 

 atomic weights of the constituents. 4*57 approaches so nearly 

 to 4 atoms of water that I considered myself entitled to conclude 

 that the salt is a compound of 



2 atoms sulphuric acid 10*0 



1 atom soda 4*0 



4 atoms water 4*5 



18-5 



To verify this supposition, 18*5 grains of the salt were dissolved 

 iu water and mixed with a solution of 26*5 grains of chloride of 

 barium. After the sulphate of barytes had precipitated, the 

 supernatant liquid was tested by sulphate of soda and muriate 

 of barytes, but was not affected by either. It therefore contained 

 no sulphuric acid nor barytes, showing that 18*5 is the true 

 atomic weight of the salt, and consequently that its constituents 

 have been rightly determined. 



The specific gravity of anhydrous sulphate of soda 2*640 



of crystallized sulphate cf soda 1*350 



— — of bisulphate of soda 1*800 



of sesquisulphate of soda 2*260 



It is a curious circumstance that in these three salts both the 

 water of crystallization and the surplus acid (in the bisulphate 

 and sesquisulphate) have undergone an expansion instead of 



