( 129 ) 



Very completely cleavable towards !>. 



The optical axial plane jOOlj whilst h is the first diagonal. The 

 axial angle is small, the dispersion strong and perhaps abnormal. 

 It was not possible to properly characterise it with the means at 

 my disposal. 



The sp. gr. of the crystals is 1,296, at 19° ; the equivalent 

 volume 127,31. 



Topical axes : x : V' ^ ^ = 5,1358 : 6,1099 : 4,0569. 



On account of the symbol |201| the relation /; : c = 1 : 0,6640 has 

 been taken. 



3. 1-4-Nitro-Metliyl-Phenyl-Carbamic Methyl- ester. 



C,H, (NO J . N (CHO . CO . ^CH,) ; melting point : 108° C. 



r4) (1) 



This compound crystallises from alcohol or benzene in the form 

 of small delicate needles, or large, pale-sherry coloured, somewhat 



flat crystals, which, however, 

 are very poor in planes, and, 

 therefore, do not allow of a com- 

 plete parameter-determination. 

 MonocUno-prismaiic. 

 a:b = 0,6640 : 1. 

 ^ = 70° 58'. 

 Forms observed : 

 c=:|001| generally strongly pre- 

 dominating ; 771 = jllOj well 

 developed ; b = jOlOj, narrow. 

 Often the planes of m and b are 

 curved and the crystals exhibit 

 greater anomalies in the angular 



Fig. 3. 



values. 



The habitus is mostly broadly flattened towards c, sometimes c 

 and m are equally large and the habitus consequently becomes 

 rhombohedric. 



Very completely cleavable towards [001 1. 



The optical axial plane is probably jOlOj ; on c one optical axis 

 is visible on the border of the field of vision. 



The sp. gr. of the crystrals is 1,522 at 14°; the equivalent-volume 

 ^ 137,98. 



