M. Scheerer's Observations on Elccolitk and Nephdine. 109 



iferous syenite of Fredriksvarn. It must be considered, as 

 it were, as a granite in which the quartz is replaced by elaeo- 

 lith. On account of its evident peculiarity and its large dis- 

 tribution, Professor G. Rose has proposed for it the name mi- 

 ascite (from the river Mias in the neighbourhood of its occur- 

 rence). Its specific gravity I found to be 2'60. 



Two analyses of this mineral have recently been published 

 by M. Bromeis*, who obtained the following results : 



Silica. . ' . . 42-51 



Alumina. . . . 33'73 



Peroxide of iron . trace 



Lime 0-20 



Soda . . . \ . 14-01 



Potash .... 6-91 



Magnesia . . . 0-77 



Water 0-92 



99-05 100-77 



Mr. Francis and I have likewise examined this mineral. 

 The result 8 is that which Mr. Francis obtained ; the result 9 

 that which I obtained by analysis : 



8. 9. 



Silica 44-30 44-07 



Alumina. . . . 33-25 33-12 



Peroxide of iron . 0-82 0-57 



Lime 0-32 , 0-26 



Soda 16-02 15-70 



Potash .... 5-S2 5'69 



Magnesia . . . 0-07 trace 



Water O'OO 0-90 



100-60 100-31 



The results of the two last-mentioned analyses differ from 

 those of M. Bromeis, particularly in the amount of silica. . I 

 shall subsequently return to this point. 



5. Ncpheline from Monte Somma (Vesuvius). This mineral 

 occurs very differently from the preceding ones, it always 

 being found crystallized in 6-sided prisms with terminal faces 

 perpendicular to the axis, combined with one or two hexa- 

 gonal pyramids. It is situated in cavities of the dolomite, 

 accompanied by garnet, vesuvian, anorthite, glassy felspar, 

 &c. All these minerals present exactly the appearance of 



Poffy. Annalen, vol. xlviii. p. 577. 



