B. W. Frasier — Axinite from Bethhlt* ■■„,, P< m, 



tals have usually dull, 



441 



neven surfaces, and are not fitted for 

 Some of the smaller ones, however. 

 have smooth, brilliant planes, and admit of quite accurate 

 its. Thecryatals are implanted in such a manner 

 that the planes surrounding only one extremity of the axis of 

 z'xie, /'. I, u, are developed. Adopting v. Bath's surest ion, we 

 " ''1 consider the crystal upright when it 



i that, x being 

 above*, u lies to the right" of "s. Most of the crystals examined 

 were in a reversed position. 



The same irregularities noticed by previous observers in the 

 crystals of axinite, have been observed in these aiso. The 

 planes are frequently curved, giving several reflected images of 

 the signal, occasionally they deviate slightly from the zones in 

 which they should lie ; and the results of measurement of an- 

 gles between planes giving sharp, clear reflections, and appar- 

 ently fulfilling" all conditions of regularity, differ in some eases 

 considerably from the results of calculation, the differences far 

 exceeding the probable errors of observation. 



In some of the cases where there were several reflections 

 from a plane the angle as measured by the brightest only is 

 recorded in the subjoined table. In other cases of multiple 

 reflection, where the decision was doubtful, all the measure- 

 ments are given. 



The following planes were observed on the crystals which 

 were examined, viz: />, I, u, v, w ; r, 2, m, e ; s, x. y, c, o; d, », 

 b ; 0; 0; <p. In table I the results of some of the measurements 



