228 



Canadian Record of Science. 



sary to calculate their norms. These have been found to 

 be as follows : — 





No. 



1 





No. 2 



Albite .... 





35.63 ) 







28.62 ) 



Anorthite . 





23.07 



69.82 





14.23 V 57. 90 



Orthoclase 





11.12 ) 







15.05 ) 



Nepheline. 



— 





5.40 





11.83 





( 34 CaO. Si0 2 



— 3.94 ) 





( 53 CaO. 

 \ 18 FeO. 



Si0 2 — 6.15 ) 



Diopside . . 



I 7 FeO. SiO., 



— .92^ 



7.56 



Si0 2 — 2.38 \ 12.03 

 SiO 2 — 3.50 \ 





/ 27 MgO. SiO, 



— 2.70 ) 





( 35 MgO. 



Olivine . . . 



/ 6 FeO. \ SiO., 

 I 23 MgO. | SiO 9 " 



- .61 | 



— 1.61 ) 



2.22 



/ 21 FeO. 

 \ 42 MgO 



4Si0 2 - 2.14) - os 

 iSiO, — 2.94/ 0U5 



Magnetite. 







6 26 





4.41 



Ilmenite . 







4 71 





5.01 



Apatite. . . 







2.68 





2.59 



Water .... 







.68 

 99.33 



BaO=.08 



.95 

 Excess FeO = .07 .15 



99.95 



No. 1 thus takes the following position in the classi- 

 fication in question : 



Class II, dosalane. 



Order 5, germanare. 



Rang 3, andase. 



Subrang 4, andose (grad = polmitic.) 



Its precise designation would be nepheline-bearing grano- 

 andose or in some cases nepheline-bearing tracho-andose. 



No. 2, however, belongs to the next order and is doni- 

 alkalic. Its position is as follows : 



Class II, dosalane. 



Order 6, norgare. 



Rang 2, essexase. 



Subrang 4, essexose (grad = prepolic. 



It would therefore be termed a nepheline-bearing grano- 

 essexose. It is therefore seen that the essexite from the 

 central portion of Mount Johnson (No. 2) is practically 

 identical in character and composition with the essexite 

 of the original locality of Salem, Mass. (Analysis IV), 

 while the outer andose is poorer in nepheline and has a 



