﻿86 Canadian Record of Science. 



Syntagmatite. Actinolite. 



222x60 =13320 609x60 = 36540 



56x102-6= 5745 



18x160 = 2880 



127 X 40 = 5080 457x40 = 18280 



70x 56 = 3920 152x56= 8512 



12 X 62 = 744 



9 X 94 = 846 



3x 18 = 72 



32607 63332 



Then, 



(32607 + 63332): (13320 + 36540) :: 100 :ic 

 and ic = 51'97 = p.c. of SiOg in the mixed hornblende. And 

 in like manner the percentages of the other constituents 

 are calculated. 



But 32607 : 63332 practically as 1 : 2, and therefore the 

 formula of the Edenville hornblende might be regarded as 



EsRlsigOia + 2(Mg3CaSi40i2) 

 or as Scharizer gives it 



10(R3R2Si3Oi,) + 20(Mg2CaSi4O,,) 

 The analyses selected by Scharizer agree remarkably 

 well with this theory, but there are aluminous horn- 

 blendes whose constitution cannot be readily explained in 

 this way and which at the same time cannot be referred 

 to the pargasite orthosilicate.^ 



Garnet. — In the hand specimens the garnet is seen 

 to possess a deep reddish-brown color. In the thin 

 sections it is a paler brown although still deeply colored. 

 It is not found in all parts of the mass and where it does 

 occur is usually present only in small amount. It 

 possesses the usual high index of refraction and is quite 

 isotropic, occurring usually in irregular shaped grains but 

 in some few cases showing distinct crystalline form. It 

 frequently holds a few large inclusions which usually 

 consist of calcite in single individuals, although the garnet 



1 See Scliarizer's paper, loc. cit , p. 156. 



