From STRONTIUM. ^ 



the expiration of this time, the crucible itfelf became foft and 

 from being turned in the fire was diftorted in its fliape Un 

 examination after cooling, part of the fpar was found to have 

 undergone fufion, and was converted into a glafi of a bottle- 

 green colour. The vitrified portion occupied the furface ; the 

 internal part was to appearance fimilar to the refult of the laft 

 experiment, but it felt much lighter. It now had an acrimo- 

 nious tafte ; it attracfled water with great avidity, and imbibed 

 it with a hifling nolfe ; it was rendered foluble in this fluid. 

 The lofs of weight which the fpar fuftains when the aflion of 

 the fire has produced its fulled efFe<fl, amounts to 38.79 per cent. 

 When a little water is poured on the calcined mineral, it fwells^ 

 burfts with a hifling noife, and becomes hot with more rapidity 

 and in a greater degree than lime ; like it, it falls into a dry 

 powder, but the particles are not fo fine. 



The powder unites with acids into the fame fort of com- 

 pounds as before, but no effervefcence attends the combination* 

 When the glafs Is dropped into muriatic acid, it is flowly adled 

 upon ; at length a jelly is formed, which becomes perfedlly 

 fluid on the addition of water, a minute portion of powdery 

 matter, which probably comes from the crucible, remaining 

 undiffblved. If the calcined fpar be left expofed to the atmo- 

 fpheric air, in the courfe of twenty-four hours, it fwells, 

 cracks and crumbles into powder, at the fame time attrading 

 carbonic acid, and becoming effervefcent. 



14. Under the blowpipe the fpar becomes white and opaque, 

 and lofes a part of its carbonic acid. I have not been able to 

 vitrify it per fe. With borax, mineral alkali and microfmic 

 fait, it melts readily into a white vitreous matter. An ^effervef- 

 cence attends the fufion, particularly when borax is employed. 



15. It appears from the experiments already recited, that the 

 Strontian mineral lofes a greater weight when fubjeded to heat 

 than during folution in acids. This mufl; be afcribed to the ex- 

 pulfion of moifliure in the one cafe, and the retention of it in 



the 



