3 1 6 HabUtida and Comliiiat'ioni ef 



decompofcd. Sulphurated liyJrogciie gas is formed j and at the extremity of the tube oppDfito 

 to that at which the gafcs were introduced, very iibuiidiuit cryllals of fulphur are dcpofiied. 



Hydrogenc therefore, at an elevated temperature, has more affinity with oxygcne than 

 fulphur has. Confequently it is not probable, as fome perfoiis imagine, that fulphur may 

 be burned by means of water to convert it into fulphuric acid. 



The /iBion of Pliofphcriis.] Thofphorus does not alter the fiilphureous acid. When thefe 

 two fubftanccs are llrongly heated in a glafs tube, nothing paflcs which indicates the 

 decompofition of the fulphurcous acid. The phofphorus becomes fixed in cooling in the 

 form of tranfparent drops which do not contain an atom of fulphur, and the fulphurcous 

 acid gas is ftill found to poflefs all its properties. 



In this cafo, therefore, there is a flronger adhefion between the fulphur and oxygene than 

 between the phofphorus and the fame principle. And accordingly this combulUble fub- 

 ftance, heated with fulphuric acid, does not deprive it of more oxygene than exceeded the 

 conflilution of the fulphurcous acid. 



Ailian c.f Phofphiratfd HyJroginie Gas."] As foon as the fulphureous acid gas and phofpho- 

 ratcd hydrogene gas come into contact, a white fume appears, and they lofe their fluid flate. 

 Plates of a yellow matter are precipitated on the fides of the containing vellcl, which take 

 fire on a hot iron, firft, in the manner of phofphorus, and afterwards with the chatadters 

 of fulphur. It follows from this experiment, that the hydrogene is the only fubftance which 

 burns, or combines with oxygene, in thefe circumftances, fince the gafes lofe their elafticity, 

 and the phofphorus and fulphur are found combined together. 



ABkn of Sulphurated Hydrogeiii Cai.^ The fulphureous acid gas is decompofcd by tlie 

 fulphurated hydrogene gas. The hydrogene takes the oxygene from the fulphur, and tliis lafl 

 principle is feparated on both fides. It therefore forms a very abundant depofition. When 

 thefe gafes are diflblved in water, they mutually undergo the fame decompofition, and the 

 fulphur then precipitates to the bottom of the liquor *. If fuitablc quantities of thefe folutions 

 be taken, the odour of both difappears. 



Anion of Carhone.'S We paded fulphurcous acid gas through a tube of glafs containing 

 ignited charcoal. At the extremity of the apparatus cryllallizcd fulphur was d^pofited, and 

 carbonic acid was produced, together with a fmall quantity of fulphurated liydrogene gas, 

 from a portion of the water which was decompofcd. This decompofition does not take 

 place in the cold. 



VII. Ccinbincthns of the Sulphureous Acid with Alialis. 



THE fulphureoBS acid readily unites with alkalis and earths. The generic nameof fulphitcs 

 has been given to thefe combinations. They may be prepared in two ways ; either by pre- 

 fenting the aqueous folution of the fulphureous acid to the bafes, or by applying the acid in 

 the (late .of gas to thefe bodies, either diiTolved or mixed with water. The latter method is 

 preferable, for feveral reafons too long to be detailed here. 



The fulphureous acid bei.'ig very different from the fulphuric acid, it may eafily be con- 

 ceived that its combinations ought to pofiefs properties not at all rcfembling thofc of the 

 fulphatcs. It will in fa6t be feen, that thefe falts poflefs peculiarities of tailc, folubility 

 and form, which belong only to thcmfclves ; and tliat tliey are fubjeft to laws of attradion 

 and decojTipofition altogether difl^erent from thofe of the fulphatcs. 



- Fourcroy, An.)lyfe dc 1' Eau d'EDghicn. 



The 



