OF THE WESTEKj!^ ISLES OF SCOTLAND. 



349 



of propylites of the Western Isles of Scotland and those of Hungary 

 and Transylvania, on the one hand, and of the Western States of 

 North America, on the other, the chief districts in which they have 

 been studied. 



As a type of the analyses of the more acid varieties of the Scottish 

 prop5']ite we may cite that of the rock of Beinn Talaidh — a horn- 

 blende-andesite passing into a diorite — placing side by side with it 

 a European and an American rock of analogous constitution. 



I. 11. III. 



Silica 62-81) 03-05 03-13 



Alumina 14-8-1: 14-18 10-00 



Perric oxide 9-20 4-34 



Perrons oxide 0*71 1*52 



Manganic oxide . . trace 



Lime 3-01 o-40 445 



Magnesia 0-37 1-12 2*07 



Soda 4-01 5-05 3-87 



Potash 2-91 3-49 2-05 



Loss on ignition . . 1*41 2-04 2-00 



Total 99-24 101-04 100-03 



I. Analysis of highly crystalline horiiblende-propylite from the 

 deep Corry in Eeinn Talaidh, Mull, made by T. H. Holland, 1889. 



II. Analysis of hornblendc-andesitc (propylite) from Tokay 

 (Banhof), Hungary, by K. v. Hauer, Yerh. k.-k. geol. Ileichsanst. 

 1809, p. 140. 



III. Analysis of hornblende-mica-andosite (propylite) from Cross 

 Spur Quarry, Washoe, made by R. W. AYoodward, 1875. 



A good type of the more basic pyroxene- propylites of the Western 

 Isles of Scotland is found in the much altered rocks exposed on the 

 western slopes of the Beinn More in Mull, and between that moun- 

 tain and^A Chioch. Anal5'ses of European and American rocks are 

 added for comparison with it. 



I. IL III. 



Silica 58-07 59-50 58-44 



Alumina 17-02 20-38 18-17 



Perric oxide .... 4-97 5-87 



Perrons oxide .... 3-09 .... 6-03 



Manganic oxide . . traces 



Lime 5-23 6-82 0-19 



Magnesia 1-46 3-71 2-40 



Soda 3-31 1-49 3-20 



Potash 2-15 1-25 1-97 



Loss on ignition . . 4*15 1*85 3-03* 



Total 100-05 100-93 100-03 



* Including 2<S7 per cent, of Carbonic Acid. 



