83 PHYSIOGRAPHY. CLASS II. 



case ; and no doubt can remain, that the determination of 

 HAU y, who first united the Flosfcrri with his Arragonite^ is 

 perfectly correct and conformable to nature *. 



2. With regard to the chemical relations, the species of 

 prismatic Lime-haloide is particularly remarkable. For a 

 long time the most accurate analytical chemists were not 

 capable of finding the smallest difference in the mixture of 

 prismatic and of rhombohedral Lime-haloide. Professor 

 STROMEYER succeeded in discovering in several varieties of 

 the former, a small proportion of carbonate of strontites and 

 water. According to the very exact analyses of this che- 

 mist, the varieties of prismatic Lime-haloide consist of 



Carbonate of Lime 05-2965.. .99-2922. 



Carbonate of Strontites 0-5090... 4-1043. 



Water 0-1544... 0-5992. 



The carbonate of strontites does not exist in constant 

 proportions, and has not been found at all in the coralloidal 

 varieties. For this reason several mineralogists still con- 

 sider the varieties of Flosferri as different from the species 

 of prismatic Lime-haloide. Thin fragments of transparent 

 crystals decrepitate in the flame of a candle ; other varieties 

 lose their transparency, and become friable. It phospho- 

 resces upon red-hot iron, and is soluble in nitric and muria- 

 tic acid, during which process the carbonic acid is disen- 

 gaged. 



* In every variety of this species, which consists of 

 columnar particles of composition, traces of cleavage in 

 longitudinal directions are observable, and produce that 

 characteristic silky lustre, which appears in Satin-spar; 

 while in every variety of the rhombohedral species, traces 

 of the inclined faces of cleavage remain, though the com- 

 ponent individuals be ever so small. There are varieties 

 in which the two species are joined longitudinally in si- 

 milar compositions. Still more frequently the two species 

 alternate in layers perpendicular to the direction of the 

 fibres, in which case those of prismatic Lime-haloide gene- 

 rally possess lower degrees of transparency than those of 

 the rhombohedral species. H. 



