ANHYDROUS SULPHURIC AND SULPHUROUS ACIDS, 44:7 
The substance contains more sulphuric acid when it is not analysed 
immediately after preparation, and after it has given forth some sul- 
phurous acid ; less sulphuric acid, on the contrary, when this was the 
case, and it therefore contained some free sulphurous acid. 
The result of these four experiments carefully conducted, according 
as the substance was of newer or older preparation, was as follows: 
Weight of Weight of sulphate Percentage of 
Compound. of baryta obtained. sulphuric acid. 
I. O29 (ere seed PSE22 Pra 8k 72-90 
IL. DOD? pe Meche es Deo gree teaccte 70°00 
III Bi i a a POM ON. 68°91 
IV. PHSOrS Ue as SPOZL Ma A 67°68. 
The compound does not contain, therefore, as I suspected before the 
experiment, sulphuric and sulphurous acids in the same proportions as 
in the anhydrous hyposulphuric acid (S + S), but 2eq. of sulphuric 
acid to 1 eq. of sulphurous acid (2S + S) which in 100 parts may be 
stated as follows : 
ep hiiries AIM, ede. bs san vcysbiisndeecendeoeond 71°42 
murhierous acid): c6or ce Beek dete casiaee 28°58 
100:00 
As the sulphurous is the least strong acid in the combination, and 
may therefore be considered of the two as the base, according to this 
view the compound may be considered as a neutral sulphate salt, in 
which the sulphuric acid contains three times as much oxygen as the 
base. 
