i8 ACCOUNT' of a MINERAL 



effervefcence and folution took place ; and this happened when 

 fimilar fparing quantities were thrown in for two or three 

 times, after which the powder united with gentle effervefcence, 

 and fell to the bottom. I poured Strontitic water into a fimilar 

 folution of the acid ; at firft no difturbance of tranfparency 

 was obfervable, but when the point of faturation was not far 

 diftant, a copious precipitate appeared. This I walhed with 

 cold water, that feems to a6l little upon it, and diflfolved it in 

 boiling, of which it requires about an hundred and thirty 

 times its own weight. The folution changes to a green, the co- 

 lour of paper ftained with the juice of violets. 



With Carbonic Acid. 



44. The combination of Strontites with carbonic acid we 

 have in the Strontian mineral, the properties of which I have 

 been detailing. The earth, foluble in water, becomes fcarcely 

 fo by uniting with this acid. With an excefs of acid its folu- 

 bility increafes confiderably, as is the cafe with barytes and 

 lime. The folution of Strontites is precipitated by water im- 

 pregnated with carbonic acid, and the precipitate is redilTolved 

 by the addition of more of the fame fluid. 



45. Strontites, and all its combinations, poffefs a remark- 

 able property, and one which I long confidered as peculiar to 

 them : I allude to the quality of tinging the flame of combu- 

 ftible bodies of a red colour. The muriate has this power in 

 the moft eminent degree. Its eflecSls are well exhibited by put- 

 ting a portion of the fait on the wick of a candle ; it caufes 

 the flame to aflume a beautiful deep blood-red colour. All the 

 other compounds, and Strontites itfelf, occafion more or lefs of 

 the fame appearance. The nitrate approaches the neareft to the 

 muriate ; and it is in confequence of this property that the de- 

 flagration of this fait with an inflammable fubfl:ance exhibits fo 

 brilliant and vivid a red flame. It is a pretty experiment to ex- 



tinguifli. 



