BY JAMES M. PETRIE. 857 



ill the open, appai'ently it was uul coinl)iiied as hydrate in the 

 crystals. 



Tlie liy(h-ates <)l)tained by Ma<|ueiiiie and others were only 

 decomposed at 100°C. If the hydrate exists in the above case, 

 it is decomposed by drying at the ordinaiy temperature. 



The l;*^vo-inosit()] of this research, therefore, was obtained in 

 anhydrous crystals only. The hydrates prepared Ijy the French 

 chemists could not be obtained. 



The substance isolated from HebrorhDidron olcrvfoliiDit is thus 

 })roved to be the methyl ester of l(e.vo-rof(Uor}j inositol. 



(12) Crystal Form, — -The outward structure and measurements 

 of the crystal forms are intimately related to the internal struc- 

 ture of the isomeric molecules, and, therefore, form an essential 

 part in the elucidation of the individual members of a group. 

 The methyl inositols apparently have never been examined by 

 crystal lographers, and indeed, as far as the author can ascertain, 

 only inactive inositol crystals have been examined by the goni- 

 ometer. 



The goniometric determinations of the crystal forms of 1. -methyl 

 inositol were kindly made by Dr. C. Anderson, Mineralogist to 

 the Australian Museum, and are here included. 



CrYvStal Measurements of Methyl L.Evo-ixosrroi.. 

 By Charles Anderson, M.A., D.Sc. 

 The crystals are small, the largest being about 2 mm. in length. 

 They belong to the orthorhorabic system and are very uniform 

 in development and habit: of the five crystals measured, fuur 

 sliow the forms a(lOO), 6(0 10), m(llO), ^(011), wdiile one has, in 

 addition, one face of the form /'(lOl), and they are all tabular 

 on a. The faces are by no means perfect, being interrupted and 

 wavy, the signals are only fair, and, consequently, the measure- 

 ments are not m close agreement. The crystals were measured 

 on a two-circle goniometer, the reducing lens being used. 



