220 



Canadian Record of Science. 



side of the mountain, the hornblende was found free from 

 inclusions, and practically free from the pyroxene which 

 is usually so intimately associated with it. From this 

 locality a quantity of the hornblende was obtained in a 

 state of perfect purity through repeated separations by 

 means of Klein's solution, all grains of foreign mineral 

 still remaining being finally removed by picking them out 

 by hand with the aid of a powerful lens. The pure 

 material thus obtained was analysed by Professor Norton 

 Evans, of the McGill University, every precaution to 

 secure accuracy being observed and especial care being 

 taken to effect a complete separation of the magnesia from 

 the alumina by the repeated precipitation of the latter. 

 The water was estimated by a direct determination. The 

 results of the analysis are given below, together with 

 those of several other hornblendes of similar composition 

 which have been added for purposes of comparison : 





No. 1 



No. 2 



No. 3 



No. 4 



No. 5 



No. 6 



Si0 2 



Ti0 4 



Al 2 3 



Fe 2 3 



FeO 



MnO 



MgO 



CaO 



Na 2 



K 2 



38.633 

 5.035 



11.974 

 3.903 



11.523 

 0.729 



10.200 



12.807 

 3.139 

 1.489 

 0.330 



39.75 

 5.40 



15.00 

 7.86 

 2.89 



14.16 



12.97 



1.92 



1.61 



101.56 



40.15 

 5.21 



14 34 

 7.80 

 4.53 



13.14 



11.75 

 2.31 



1.14 



40.14 

 4.26 



14.30 

 7.07 

 6.27 

 0.21 



11.62 



12.00 

 2.22 

 1.35 



41.35 

 4.97 



13.48 

 5.14 



10.33 



11.44 



10.93 



2.10 



0.62 



0.48 



39.16 



14.39 



12.42 



5.85 



1.50 



10.52 



11.18 



2.48 



2.01 



H 2 



0.39 





99 . 762 



100.37 



99.44 



100.84 



99.90 



No. 1. Hornblende. From the essexite of Mount Johnson, province 



of Quebec, Canada. 

 No. 2. Hornblende. From Bohemian Mittelgebirge. 

 No. 3. Hornblende. From tuff of hornblende basalt, Hartlingen, 



Nassau. 

 No. 4. Hornblende. 

 No. 5. Hornblende. 



Weilburg. 

 No. 6. Hornblend. Syntagmatite. Jan Mayen. 



Analyses Nos. 2 to 6 are taken from Schneider's paper referred to 

 below. 



Basalt tuff, Hoheberg, near Giessen. 



From "hornblende diabase," Graveneck, near 



