NATIVE SULPHATE OP MAGNESIA. 28$ 



1. To a dram of the aqueous folution, 20 quarts of folution 

 of the muriate ofbarites were added, and a copious, denfe, 

 white precipitate was inftantly produced. 



2i Equal parts of the aqueous folution and lime water, 

 when added together, formed a cloud which gradually fub- 

 fided. 



3. Twenty drops of pure potafli were added to a dram of 

 the folution, and a copious precipitate was inftantly produced. 



4. To a dram of the folution were added two drams of a 

 folution of the carbonate of potafli, a flocculent precipitate 

 was immediately produced. 



5. A very copious precipitate was produced,, when twenty 

 drops of pure ammonia were added to a dram of the folution. 



6. The oxalic acid produced no action when added to the 

 folution. 



7. Ten drops of the nitrate of (liver being added to the 

 aqueous folution, produced fcarcely any effect ; a (light milki- 

 nefs only was perceptible in the fluid. 



From thefe experiments the nature of the fait is fufficiently It was fulphato 



evident ; the action of the muriate of barites proves it to be a °f ma gnefia. 

 i-ii it • -i»- ,ti Remarks. 



tulphate, and the experiments with lime water and the alca- 



lis, (hew that the fulphuric acid is United to magnefia. From 



the 6th experiment we find that it contains no lime, and from 



the 7th, that it contains only a very minute portion of muriatic 



acid. It appears therefore to be the fulphate of magnefia, or 



Epfom fait, in almofi a perfectly pure ftate. The fulphate of 



magnefia, which is ufually met with in commerce, contains a 



considerable proportion of muriatic acid ; this is proved by the" 



very copious precipitate which it will be found to yield upon 



the addition of the nitrate of (ilver. To the muriatic acid 



which it contains, Bergmann afcribes the tendency which the 



common fulphate of magnefia poffeffes, of attracting moifture 



from the atmofphere. 



The; refult of thefe experiments were not what I expected ; 

 I imagined that the efflorefcences which we occafionally ob- 

 ferved on walls, were compofed for the mpft part of the nitrate 

 of potafh. The purity of the fait was alfo a circumftance 

 which appeared curious, as being contrary to the ftate in 

 which we ufually find it. The mod Angular circumftance, 

 however, was its appearing at all in that fituation. 



V.9L. III.— December, 1802. U Upon 



