From SfRONfUN, n 



With Nitrous Acid. 



23. When the nitrous acid in its ftrongeft flate is poured on 

 a mafs of native carbonate of Strontites, no adlion enfues ; but 

 if fome water be added, the acid commences to adl with ener- 

 gy, and a folution, attended with a brifk efFervefcence, is the 

 confequence. Very Httle will be difTolved, though the fpar be 

 finely powdered, if the acid be highly concentrated. A fmall 

 increafe of temperature, it may be remarked, enables the ftrong 

 acid to attack the folid fpar, and to accomplilh the folution. If 

 you employ an acid previoufly diluted, the ebullition inftantly 

 begins ; for this purpofe, an equal quantity of water at leaft 

 muft be mixed with the acid. If much lefs be added, the ef- 

 fervefcence and folution will commence, but they will both foon 

 ceafe. When the quantity of water is fufEcient, the acid free 

 from adulteration, and the fpar pure, no reliduum is left, and 

 a clear and tranfparent folution is obtained j but if fomewhat 

 lefs of the water be employed, the fait that is formed by the 

 union of the acid and earth immediately afTumes a folid cryftal- 

 line form. It was by a folution carried on in this manner that 

 I procured the mod regular, though by no means the largeffc 

 cryftals of this nitrate. 



24. The folution has a ftrong pungent tafte. It is perfeflly 

 neutral, and readily by evaporation yields cryftals. Thefe are 

 rarely produced in fo regular a manner that their form can be 

 eafily afcertained. By a flow and fpontaneous evaporation, cry- 

 ftals were formed that were hexagonal truncated pyramids. The 

 moft perfecfl cryftals, obtained in the way a little ago defcrlbed, 

 were odlohedral, conlifting of two four fided pyramids united 

 by their bafes. Sometimes the apex is truncated, and the cry- 

 ftals terminate like a wedge ; often likewife the angles are trun- 

 cated in different degrees, which gives a confiderable variety to 

 the ftiape of the cryftals. 



B 2 25. This 



