OF CENTRAL CANADA PART II. 109 



is referred to it by Dr. Sterry Hunt. Report for 1863, p. 478. 

 Average composition : silica 59J, alumina 25|, lime 7|, soda 5, 

 potash 1. Sp. gr. 2.662.67. 



62. Anorthite : This species is also very closely related to both 

 Labradorite and Albite. It occurs in Triclinic crystals and cleavable 

 masses of a greenish-white, reddish, pale-grey and other colour, with 

 H = 6 6.5, and sp. gr. 2.66 =2.79. Fusible, and more or less 

 readily decomposed by hydrochloric acid. Average composition : 

 silica 44 47, alumina 30 35, lime 14 18; with small per- 

 centage of soda, potash, &c. A variety found in boulders in the 

 vicinity of Ottawa city was originally described under the name of 

 Bytownite. Some of the feldspar of Chateau Richer, according to 

 Dr. Sterry Hunt, belongs probably to this species. The feldspar 

 which enters into the composition of the diorite of the Yamaska 

 Mountain is also referred to it by the same observer; and fine 

 crystals of Anorthite, according to Mr. Thomas Macfarlane, occur in 

 a large dyke of dioritic porphyry, of which several rocky islets in the 

 vicinity of Thunder Cape, Lake Superior, are mainly composed. 



% The two following species are placed for convenience in this group, as 

 they are essentially lime-containing silicates, fusible, and decomposable in hy- 

 drochloric acid. 



63. Wernerite or Scapolite : White, grey, red, greenish, &c. 

 Occurring in crystals of the Tetrrgonal System (mostly combinations 

 of a square-based prism and pyramid), and in lamellar, columnar 

 and sub-fibrous masses. H = 5.5 6.0 (under normal conditions, 

 but often somewhat lower from incipient decomposition of the 

 specimen) ; sp. gr. 2.6 2.8. BB, easily fusible, mostly with strong 

 bubbling. Partially decomposed by hydrochloric acid. Average 

 composition : silica 48, alumina 28, lime 18, soda 5, the latter some- 

 times largely replaced by potash. Carbonate of lime and a small 

 percentage of water are very constantly present in altered or 

 weathered specimens. Scapolite occurs in the Laurentian limestones 

 of Calumet Island, and in Grenville Township, on the Ottawa, as 

 well as in most of the phosphate deposits of the Ottawa region. 

 Also in large crystals and cleavable masses, with sphene and augite, 

 in the Laurentian strata of Hunterstown, Maskinonge County, 

 Quebec; and at Golden Lake, in Algona Township, County of 

 Renfrew. An altered or semi-decomposed variety in violet-red or 



