Formation of Sulphuric Acid. 96 



6. 160 grains of the dry saline matter were put into a 

 retort mixed with water and the deutoxide of azote collected 

 as it was extricated. The quantity of this gas evolved, 

 supposing the thermometer at 60° and the barometer at 30 

 inches was 59'35 cubic inches. 



The liquid in the retort being freed from the sulphite 

 of lead, was found to be a solution of sulphuric acid in 

 water, without any trace of nitric or sulphurous acid. 

 This sulphuric acid being obtained partly in the state of 

 sulphate of soda, and partly of sulphate of barytes, 

 amounted to 132-24 grains= 105*79 grains of sulphurous 

 acid. 



The weight of the nitrous gas obtained was 19*17 equi- 

 valent to 34*5 grains of nitric acid. 



The constituents obtained were, 



Sulphurous acid . . . 105*79 



Nitric acid 34-50 



Sulphite of lead ... 1*40 



141*69 

 Loss 18*31 



160* 

 This loss must be water. The constituents then are very 

 nearly 



1 atom nitric acid .... 6*75 

 5 atoms sulphurous acid . . 20*00 

 3 atoms water ...*.. 3*375 



30*125 

 That the acid present is nitric and not hyponitrous I 

 infer from the phenomena of the distillation of the saline 

 matter. And from our knowledge of the fact that nitric 

 acid is actually introduced into the leaden chambers along 

 with sulphurous acid, and there being nothing present to 

 convert it into hyponitrous. 



There is no evidence from the analysis that the whole 

 acid of sulphur was in the state of sulphurous acid. I am 

 induced from the proportions found to suspect that |^ths of 

 it was in the state of sulphuric acid, and fihs, in that of 

 sulphurous acid. On that supposition it is easy to see how 

 the atom of nitric acid, by giving out 3 atoms of oxygen, 



