Intelligence and Miscellaneous Articles. 533 



o-r .^ Oxygen. 



f'llica 46-8 24-32.. 13 



Magnesia 333 1 



Lime 0-7 / 1310.. 7 



Oxide of iron. ..... 04 T 



Oxide of manganese, a trace > 3-87 . . 2 



Alumina 8'0 J 



^, Water 11-0 9-86 .. 5 



= 2 M S, + A S + 2 aq. 



PRASEOLITE. 

 M. Erdmann has described a mineral under the name of Praseolite 

 found near Brevig in Norway by Pastor Esmark. It is imbedded in 

 granite and chlorite, and is accompanied by titanite of iron and tour- 

 mahne. It is irregularly crystallized in four-sided prisms, and some- 

 times with SIX. eight, and twelve sides; the angles are rounded as 

 If fused. Colour green, light green, and dark green. Has only one 

 cleavage, and a splintery, flat conchoidal fracture, with little lustre 

 Hardness between fluor spar and calcareous spar ; gives a lio-ht green 

 powder; specific gravity 2754. Gives out before the blowpfpe water 

 not acid; the thin edges fuse with great difficulty into a bluish 

 green glass. Dissolves in borax and salt of phosphorus, giving an 

 iron colour, leaving with the latter a residue of silica ; fuses ^th 

 soda with difficulty into a yellowish green glass. It is composed of 



o-T Oxygen. 



Silica 40-94 21-268. 3 



Alumina 28-79 13746 .. 2 



Protoxide of iron 6-961 



Protoxide of manganese 0-32 > 6-969 . 1 



Magnesia 13-73 J 



^ater 7-38 6-56O .. 1 



Oxides of lead, copper") 



and cobalt S 0-50 



Lime J 



Titanic acid 040 



Formula Mg"! 



F >S-|-2AS + aq. 

 Mn J 



ESMARKITE, 



Under the name of Esmarkite M. Erdmann has described another 

 new mineral found close to praseolite, also imbedded in granite It 

 IS found in large irregular prismatic crystals, with the angles rounded 

 and generally covered with mica. The crystals have a distinct 

 cleavage at right angles to the principal axis, with a slight pearly 

 lustre ; the perpendicular fracture is uneven and of a waxy lustre 

 Hardness between calcareous spar and fluor spar; specific gravity 

 2-709. Gives off water before the blowpii)e. and becomes of a bluish 

 gray colour. Melts at the edges into a grayish glass. Salt of phos- 

 phorus and borax dl^,s(.Ive it with the colour indicating iron. Gives 

 a yellow slag with -uda. It is composed of 



