390 Slrontian in ArragonUe. 



cent, of arragonite. He has subsequently published a volu- 

 minous Latin memoir, detailing all the experiments necessary 

 to confirm this discovery. ' 



M. Stromayer's opinion being directly contradictory to those 

 of a great number of respectable French and English chemists, 

 M. Haiiy requested me to examine the arragonite of Auvergne. 

 I readily complied, being curious to examine a fact denied by 

 one and affirmed by another. After a few attempts, I informed 

 M. Haiiy that I had indeed found a saline substance which 

 could neither be nitrate of lime, as it was insoluble in alcohol, 

 and did not become moist in the air, nor lime resulting from the 

 decomposition of a portion of nitrate, if I might judge from its 

 great solubility in water, which besides did not become the least 

 turbid in contact with air. Having this substance only in the 

 state of powder, in order to satisfy myself of its nature, I waited 

 till by spontaneous crystallization it should present regular cry- 

 stals. The first specimen of the crystals which I obtained, 

 evinced the properties of nitrate of strontian ; they are trans- 

 parent, solid, unchangeable in the air, of a sharp acrid taste, of 

 a very regular octohedral form, and give a purple colour to the 

 flame of a taper. If these crystals were not nitrate of strontian, 

 they might be nitrate of barytes ; but if barytes was the base, 

 the uncertainty respecting the existence of strontian in arrago- 

 nite would soon vanish. On the other hand, this uncertainty 

 could never have existed, if Professor Stromayer's process had 

 been strictly followed, since it has been known to the French 

 chemists, who probably overlooked the strontian because they 

 did not use the same means of detecting it. 



" The process of Stromayer is susceptible of abridgement ; 

 this chemist left exposed to the air the nitrate of lime evaporated 

 to the consistence of honey, until it became liquefied, and the 

 crystals of nitrate of strontian were deposited ; but we may im- 

 mediately treat the evaporated mass with alcohol, which dissolves 

 only the nitrate of lime without sensibly aiFecting the nitrate of 

 strontian. We may uash the insoluble crystalline powder in al- 

 cohol, then dissolve it in a small quantity of warm water, and 

 leave it to crystallize. 



" This discovery of Stromayer is an additional testimony in 

 favour of the superior accuracy and utility of crystallography to 

 the sciences of mineralogy and geology, and also to chemistry 

 itself. Had not the father of crystallographic science so clearly 

 and firmly maintained the diversity of primitive structure in ar- 

 ragonite and carbonates of limo, chemists would not again have 

 thought of looking for any dissimilarity in their chemical con- 

 stitution, after the number of respectable analysts who have pro- 

 nounced 



