ON THE COMPOUNDS OF SUirHUR AND OXYGEN. Q'^ 



we learn, that fulphurous acid is compofed of 23.2 fulphuric 

 acid, and 5.1 fulphur, which gives us 



82 fulphuric acid 



18 fulphur 



J 00 

 But 100 parts of fulphuric acid contain 39 of oxygen ; there= 

 fore 82 contain nearly 32. Hence fulphurous acid is com= 

 pofed of 68 fulphur 



32 oxygen 



100 



Fourcroy affirms, that fulphurous acid contains only about 15 

 per cent, of oxygen, which is lefs than one half of the refult 

 juft given. But he quotes no experiment in proof of his affer- 

 tion. In all probability it was a mere guefs. 



6. The phenomena which attend the acidification of ful-Sulphurous acid 

 phur and the decompofition of fulphurous acid, render it pro-fulphur^'coinbin- 

 bable that fulphurous acid is rather a compound of fulphuric ed with fulphtt» 

 acid and fwiphur, than of fulphur and oxygen. '"^ ^^' ' 



Sulphur and fulphuric acid combine with great facility. 

 For if we form them into a probe, a very moderate heat is 

 fufficient to convert the whole into fulphurous acid gas. 



Whenever fulphur is acidified, a portion of fulphuric acid 

 always makes its appearance in whatever way the procefs is 

 conduced. Such at leaft; has been the conftant refult of ray- 

 experiments. 



When fulphur is expofed to the heat of an Argand lamp 

 in a retort conne6ted with a mercurial air holder, it melts and 

 fublimes at firft rapidly, but much more flowly, when the pro- 

 cefs has continued for fome time. In a retort, whofe capa- 

 city was 63 cubic inches, four hours elapfed before J oz. of 

 fulphur was fublimed into its neck. A confiderable quantity 

 of air was driven over ; but on allowing the vefTels to cool, 

 the whole returned again, except 3 cubic inches. So that, 

 by the operation, the air in the retort had increafed about 

 "Tothpart. It fmelt very pungently of fulphurous acid. When 

 agitated in water, a fmall portion of it difappeared. The 

 water did not acquire a perceptible tafte, but it precipitated 

 muriate of barytes even after being boiled for fome time. A 

 portion of this air, after being well wafhed, was left in con- 

 tad with a flick of phofphorus over water. Its bulk was di- 



VoL. VI. — October, 1803. H miniflied 



