Sulphite sf Ammoniac— Sulphite of Lime, ogj 



Baryfes, lime, and pot-a{h decompofe tlie fulphite of foda. 

 It is not foluble in alcohul. - 



Salts with bafes of pot-alli, except the carbonate, do not decompofe this fait ; the other 

 genera decompofe it like the fulphate of pot-afti. 



The metallic oxides, and their folutions in acids, have the fame effeas with the fulphite 

 of foda as with that of pot-afli. 



It contains per quintal— i. Soda :8,8;— 2. Sulphuric acid 31,2 5—3. Water 50. 

 Sulphite ofAmmomac] This fait has the form of a prifm of fix fides, terminated by fix- 

 fided pyramids. It fometimes aflumes the figure of a fquare tablet, the borders of which 

 are floped fo as to form a folid of fix irregular faces. Its tafte is cool and penetrating, like 

 that of the ammoniacal falts ; but it leaves a fulphureous impreffion in the mouth. 

 By expofure to the aiv it attrads moillure, and foon afterwards pnfles to the ftate of fulphat. 

 It IS very foluble, and requires at moft its own weight of water for its folution. 

 Heat increafes its folubility, and it cryftallizes by cooling. 

 On the fire it is volatilized without decompofition. 



Barytes, lime, pot-alli, and foda decompofe it in the cold ; magnefia produces the fimie 

 effect by the affiflance of heat. 



The acids ad on the fulphite of ammoniac in the fame manner as on thofe of pot-afh and 

 foda ; but the refults are different. 



Charcoal does not convert it into fulphuret, becaufe it rifes too fpeedily by heat. 

 It does not decompofe falts with bafes of pot-alh or of foda, but it decompofes thofe of 

 lime, magnefia, barytes, and alumine, with which it forms infoluble precipitates. 



Its habitudes with the metallic oxides and falts are nearly the fame as thofe of the ful- 

 phites of pot-afh and of foda, excepting that it forms with feveral of them triple falts, as 

 we (hall more amply explain in another memoir on the metallic fulphites. 



Its component parts in the quintal are— i. Ammoniac 29,075—2. Sulphuric acid 60 o6- 

 ^Water 10,87. ' *" 



Sulphite of Lime.} The form of the fulphite of lime is that of a Cx-fided prifm, termi- 

 nalmg m a very long pyramid. Its tafte at firft is fcarcely perceptible; but when it has been 

 kept for fome time in the mouth, it communicates to the tongue a tafte which is manifeftlv 

 fulphureous. ' 



This fait, when well neutralifed, is very fparingly foluble in water; but it becomes folu- 

 ble by an excefs of acid. In this way it may be obtained in cryftals ; that is to fay, by 

 expofing its folution in the fulphureous acid to the air. The acid is diffipated, and leaves 

 the fait in a ftate of purity. Barytes alone, among the earths, is capable of decompofing it. 

 This may be afcertained by mixing a folution of that earth with a folution of the neutral 

 fulphite of lime, when a light precipitate is formed. 



Heat converts it into fulphate, by depriving it of a portion of fulphur. 

 The mineral acids decompofe it, like the other fulphites. 

 ^JThc alkalis produce no change in this fait ; for the alkaline fulphites are dccompofcd by 



Among the neutral falts, the alkaline carbonates, as well as the alkaline phofphates and 

 fluatcs, alone decompofe it. 



It does not acquire the ftate of fulphat by contaQ of the air, but very llowly. ' 



Metallic 



