Miscellanies. 



381 



by glass, which is colored blue by nitrate of potash. Its analysis 

 proves it to be composed of 



Sulphate of baryta, . . . . 61.701 



Sulphate of Lime, 



Lime in excess, 



Carbonate of Lime, 



Silica, 



Alumina, 



Water, 



14,274 

 1.521 



8.050 

 9.712 

 2.404 



2.308 



100.00 

 This mineral is named after M. de Dree, a liberal patron of sci- 

 ence. 



3. Albite of Chesterfield. — This mineral has lately been analy- 

 zed by MM. Aug. Laurent and Ch. Holms, who have found its 

 composition to be identical with that of common albite, contrary to 

 the result of Stromeyer's analysis. The following is the composi- 

 tion determined : 



Silica, . . . . . ■ . 68.4 



Alumina, 



Iron and Manganese, 



Lime, 



Soda, 



20.8 

 0.1 

 0.2 



10.5 



100.0 



from which is deduced the formula {ZSi^ O ^ -{-AP 0=^) + (&"3 0=* -f- 

 OjYa) identical with that for the common variety of albite. — Ann. 

 de Ch. et de Ph. T. 60, p. 331. 



4. Analysis of Tabasheer from India. By Dr. Thos. Thom- 

 son.— (Rec. of Gen. Sc. No. XIV. 1836.) 



Moisture, . . . . . . 4.87 



Silica, 

 Potash, 



Peroxyd of Iron, 

 Alumina, 



90.50 

 1.10 

 0.90 

 0.40 



97.77 



