133 



and c{00l}; by a and с is understood Ihe projections in the 

 plane of the concerning axes, while a and b are in the plane 

 itself. 



The form drawn by Winther will be transformed to the 

 above one if the two crystallographic axes are interchanged, and 

 the figure is supposed to be seen from the opposite side. 



For the apparent acute axial angle in air {2Ea) Winther 

 has found 82° 40', and 1 have arrived at the same result by 

 measurings on the face ô{010) of a quite small crystal. Further 

 I have by measuring on a plate after c{00l} found the appar- 

 ent obtuse axial angle in oil (n = l*ol5) 



2Яо = 156° 



From this has been calculated the real axial angle : 



2V = 48° 3' 

 and ß = 1-622. 



For the double-refraction Winther gives on a{lOO] in 

 sodium-light 0-02711. 



1 have found, also in sodium-light 



on a{lOO} 0-0312 

 and on c{00l} 0-0275 



so that I suppose the same confusion of the faces as above 

 mentioned also to have taken place on this point in the earlier 

 description. 



Occurrence. 



As before mentioned the schizolite is found in the peg- 

 matitic veins of the sodalite syenite and in the veins of fine 

 grained albite found together with the former. Otherwise there 

 are some differences in the way of occurrence on the three 

 principal localities that are to be mentioned in the following: 



The crystals from Tu top Agdlerkofia (the principal type 

 ofWinther), with which the crystal from Siorarsuit is most 



