Mr. W. J. Lewis's Crystallograpliic Nites. 



141 



Table (continued). 





Calculated. 



Observed. 



Senarmont. 





Calculated. Observed. 



Vain 

 \_mm / 



36 57| 

 106 4| 



36 56f 

 106 6! 



O / O / 



36 45 

 106 30 106 29 



\9j m 

 mf 



1/9 



64 391 

 54 241 

 60 561 



64 43 

 54 211 

 60 59 





If a, 



73 51 

 106 54f 



73 8 

 106 591 





Inosite.- 



— This substance cryst 



allizes in colourless 



striated prisms, attached by one end to the mass of the sub- 

 stance. The striations on the planes lying in the prism-zone 

 rendered it impossible, even in the most delicate needles, to get 

 reliable measurements of the angles in this zone. The prisms 

 were terminated by four small planes, {101}, {101}, and 

 {0 1 2} , of which the former was most largely developed, some- 

 times even to the exclusion of the other planes. The crystals 

 were extremely friable, and lost a portion of their water very 

 readily — properties which rendered the examination difficult 

 and prevented the determination of their optical character. 

 The opposite faces in the zones were in all cases considerably 

 displaced, so that there was always a divergence from the zore 

 and from 180° in the sum of the angles between them. The 

 following elements and measurements can therefore only le 

 regarded as approximate. 



Fig. 3. Fig. 4. 



The system is oblique. The forms are b{0l0\, m- 

 p{2 1 0f ; {4 1 0}, 1{1 ] }, *{1 1}, *{0 1 2} (fig. 4). 



110}, 



