•<^g ON THE COMfOUNDS OF SULPHUR AND OXYGEN. 



minlflied 17 per cent. Hence it had loft 5 per cent, of oxy- 

 gen by the adion of the hot fulphur on it. Here we fee the 

 fource of the acidification of the fulphur during its fublimation. 

 From this experiment we are authorized to conclude that both 

 fulphuric and falphurous acids may be formed merely by 

 healing fulphur in couunon air, without any fenfible com.- 

 buflion. 

 Sulphur, when- Sulphuric acid feems to be formed whenever fulphur is 

 in 'part acidified! '''^^'''"^'^- ^^'^ ^^^""y fpecimen of flowers of fulphur which I 

 have had an opportunity of examining, contained that acid. 

 If common flowers of fulphur be boiled in water, the li- 

 quid always precipitates muriate of barytes. But flowers of 

 fulphur, when once they have been well waftied and dried, 

 communicate no fuch property to water. If we now fublime 

 thefe very flowers a fecond time, water in which they are 

 boiled, precipitates muriate of barytes, as at firfl. 

 Combuftion of" When a red hot glafs capfule is rapidly placed on a pedeftal of 

 iarover water, ^f^^nding water, fulphur thrown into it, and a glafs jar fuddenly 

 put over it, the combuftion of the fulphur continues for a con- 

 liderable time ; denfe bluifli-white fumes fill the jar, and at 

 laft conceal the flame completely. The fmoke foon fubfides 

 when the combuftion is over, and the water rifes flowly in the 

 jar. By this procefs, the air in the jar lofes uniformly 8 per 

 cent, of oxygen ; it retains the fmell of fulphurous acid, even 

 though allowed to remain over water for a week. But the 

 fmell di (appears in an inftant, if the air be pafled through water. 

 A portion of the water over which the jar flood, being treat- 

 ed with muriate of barytes, yielded a precipitate which 

 weighed 8. An equal portion of the fame water evaporated 

 to one-fourth, yielded a precipitate which weighed 7. 

 Aftion of acids 7. The adion of the more powerful acids upon the ful- 

 onthe fulphites. pj^i^^^ deferves attention, becaule it ferves to illuftrate the na- 

 ture of fulphurous acid. This adion has been defcribed with 

 confidcrablc minutenefs by Fourcroy and Vauquelin ; but as 

 the refult of my experiments difl^ers a little from theirs, a few 

 obfervations may not be unacceptable to the chemical reader. 

 'i"o prevent tedioufnefs, I fliall confine my remarks to fulphite 

 of potalh. 

 Aaionofful- When fulphite of potafh is thrown into concentrated ful- 

 phuric acid upon j^i^g^.jj ^ confidcrable heat is evolved, a violent effer- 

 lulphite oi pot- * . , 



2fh. vclcence takes phice, and the fait lofes 48 per cent, of i(s 



■t weight. 



