20 Canadian Record of Science. 



it polarizes. The scapolite occurs in large colorless 

 irregular individuals, and near the edge of the slide shows 

 good cleavage. In sections approaching the basal, the 

 extinction bisects the angle formed by the cleavages. 

 The mineral is clear and fresh. It separated from the 

 heavy solution at specific gravity 2.699, indicating high 

 content of lime ; these grains were heated with dilute 

 nitric acid to remove any calcite, the residue was 

 thoroughly washed, and then boiled with pure concen- 

 trated nitric acid — it was decomposed, but not entirely 

 dissolved. The solution was decanted, diluted, and to one 

 portion silver nitrate was added, a white flocculent precipi- 

 tate indicated chlorine ; the other portion was made 

 ammoniacal, and ammonium oxalate was added, an abun- 

 dant white precipitate showed lime. The hornblende is 

 green, in large individuals of angular form ; strongly pleo- 

 chroic, maximum extinction angle, 31°, indicating; a high 

 percentage of basic elements in the mineral. The augite is 

 in very irregular grains, nearly colorless to light green. 

 It shows imperfect cleavage and is also much cracked. 

 Pleochroism very slight, extinction angle 43°. 



This rock also has a typically granulitic structure, 

 being made up of a mosaic of polygonal grains. 



Amphibolite, Toivnship of Glamorgan, Lot 27, between 

 Ranges IX. and X. (Sections 1270 A.B.). 



This is a very dark, fine-grained, and friable rock, with 

 no banding apparent in the hand specimen. With the 

 aid of the microscope there is seen to be a tendency 

 toward foliation, which, however, is slight. 



The essential constituents are plagioclase and horn- 

 blende, the latter making up about two-thirds of the 

 rock. Quartz, scapolite, calcite, and augite are also 

 present in much smaller amounts. A few irregular 

 individuals of orthoclase, several irregular and broken 

 grains of sphene, associated at times with black titanic 



