104 Mineralogicul Notices. Boracite, Lazulite, &c. 

 The above results agree with the formula 



(Ca, Fe, Ma) 3 Si -f 2 Al Si, 

 and show that the mineral is chemically the same as Epidote. 



IlESULTS OF ANALYSIS OF BORACITE FROM LiJNEBURG. BY 

 M. C. RAMMELSBERG. 



[From Poggendorff's Annalcn, vol. xlix.] 



Transparent Crystals. Opake Crystals. 



S. G. 2-955 at temp. 12-5 C. S. G. 2-938 at temp. ll-5 C. 



According to 

 Arfvedson.* 



Magnesia .... 30-748 31-124 30'3 



Boracic acid . . 69-252 68-876 69'7 



The quantities of oxygen contained in the magnesia and 

 boracic acid are 12-03 and 4-7*26 respectively. Hence the 

 composition of boracite is expressed by the formula 



Mg 3 B 4 . 



RESULTS OF ANALYSES OF NOSEAN, HAUYNE, LAZULITE AND 

 ARTIFICIAL ULTRAMARINE, PERFORMED BY M. F. VARREN- 

 TRAPP IN THE LABORATORY OF PROF. HEINRICH ROSE. 



[From PoggendorfF's Annalen, vol. xlix.] 



Nosean from the Lake of Laach. 



Oxygen. 



Alumina 32-566 15-20 



Soda 17-837 4-56 



Lime 1-115 0-31 



Silica 35-993 18-70 



Sulphuric acid ... 9' 1 70 5-49 



Iron 0-041 



Chlorine 0'653 



Water 1-847 99-222 



Hauyne from Nieder-Mendig. 



Oxygen. 



Soda 9-118 2-33 



Lime 12-552 3*52 



Alumina 27'415 12-80 



Silica 35-012 18'28 



Sulphuric acid . . . 12-602 7*23 



Sulphur 0-239 



Iron 0-172 



Chlorine 0-581 



Water 0'619 98-340 



[* The details of Arfvedson's analysis will be found in Phil. Mag. First 

 Series, vol. Ixii. p. 358. EDIT.] 



