Mr Haidinger on the Specific Gravity of Minerals. 241 



tery, is not unfrequent. In the towns, chronic ophthalmia is 

 pretty common, and there appears to be an unusual propor- 

 tion of halt and lame, and that apparently from their youth. 



Art. VI. — Account of the Specific Gravity of several Mi- 

 nerals. By William Haidinger, Esq. F. R. S. E. Com- 

 municated by the Author. — ( Continued from Vol. II. p. 74.^ 



Order VI. Spar. 



I. Diatomous Schiller-spar, from the Baite in the Hartz, a species 

 generally confounded with the hemi-prismatic Schiller-spar or 

 Bronzite, 2.691 



2 Serpentine, the rock in which the former is imbedded ; it acts 

 a little upon the magnetic needle, 2.684> 



3. Hemi-prismatic Schiller-spar, the grey variety of Diallage, from 

 Monteferrato, 3.149 



4. Serpentine, accompanying it, along with Labradorite ; does not 



act upon the magnetic needle, 2.717 



5. Bionzite, of a greenish-grey colour, from Pruck, in the district 



of Pinzgau in Salzburg, 3.201 



6. Bronzite, grey, locality unknown, 3.216 



7. Bronzite, a liver-brown variety, with a particularly distinct 

 cleavage, 3.234 



8. Bronzite, clove-brown, from Bayreuth, 3.252 



9. Hypersthenic, from the coast of Labrador, 3.390 



10. Rhaetizite, a yellowish-grey variety, in long columnar com- 

 positions, little coherent, 3.545 



II. Rhaetizite, milk-white, 3.560 



12. Kyanite, deep ash-grey pebbles, from Ohlapian in Transylva- 

 nia, where it is brought along with the nigrine, 3.630 



13. K'janitc, smalt-blue crystalline masses, engaged in quartz, 



from the Saualpe in Carinthia, 3.635 



14. Kyanite, of a deep-blue, transparent, cut and polished ; a va- 

 riety to which sometimes the name of sapphire is given, 3.676 



19. Prehnite, a variety in irregularly formed crystals preserved in 



the collection at Gratz, and said to be from Elba, 2.925 



20. Spodumene, from Sweden, 3.169 



21. Datolite, a compound variety from Arendal ; the individuals 

 easily separated, 2.989 



22. Lcucite, a yellowish-grey transparent^rystal, from Green- 

 land. 2.483 



23. Sodalite, crystals, 2.295 



24. Sodalite, massive, cleavable, 2.293 



25. Mtsotype, from Auvergne, 2.24$ 



26. Natrolite, the red variety from the Tyrol, the crystals. 2.168 

 VOL. III. NO. II. OCTOBER 1825. Q 



