352 Dresser — Geology of Brorne Mountain. 



the microscope are gray, or grayish green ; those with a in the 

 same position are flesh-colored. In a few instances grains of 

 another variety of augite are possibly present, but the amounts 

 are too small to admit of satisfactory determination. 



Olivine, where present, is colorless, and is serpentinized 

 along cracks in the primary mineral. 



Biotite occurs in irregular areas having imperfect crystallo- 

 graphic outlines. 



Magnetite, sphene, apatite, and occasionally a little nepheline 

 in a decomposed condition are also present but present no 

 features worthy of further notice. 



An analysis by Mr. M. F. Connor of the Geological Survey 

 of Canada gave the result I in the following table ; II is an 

 analysis of Akerose (Essexite) from Shefford mountain, also by 

 Connor ; III, of Andose (Essexite) from Mount Johnson, and 

 IV, the original Essexite from Salem, Mass. 



I. II. III. IV. 



Si0 2 44-00 53-15 48*85 47-94 



A1 2 3 _ 27-73 17*64 19*38 17'44 



Fe 2 3 2-36 3-10 4-29 6'84 



FeO ... 3-90 4-65 4*94 6*51 



MgO _- 2-30 2-94 2-00 2'02 



CaO 13-94 5-66 7*98 ■ 7*47 



Na 2 2-36 5-00 5-44 5*63 



K 2 -45 3-10 1-91 2-79 



P 2 5 -20 -65 1-23 1-04 



Ti0 2 1*90 1-52 2-47 '20 



MnO._ -08 -46 -19 



HO -80 1-10 -68 2-04 



100-01 99-64 99-36 99'92 



The calculation of the norm of I in order to refer it to its 

 proper place in the Quantitative Classification gave the follow- 

 ing results : 



The norm of I : 



Orthoclase _.. 2*22 



Anorthite . 63*90 



Albite ._ 14-67 



Nepheline 2*84 



( l7CaOSi0 2 ) 



Diopside.. \ ]3MgOSi0 2 [ 3-80 



( 4FeOSi0 2 ) 



Olivine \ 44M S°' * Si ° 2 t 4-30 

 Olivine.. _ j 12Fe0? i Si Q 2 j--- 4 30 



Ilmenite _ 3*65 



Magnetite 3-48 



Apatite -34 



Water ..__ -80 



100-00 



