2‘IIE JOURIVAL OF I N D U S T R I A L
528
“The crystals, which were examined crystallographically, were obtained by slow crystallization from an aqueous solution of the material furnished by Fern I,. Shannon, State Analyst, Lansing, Michigan. They are prismatic in habit and about 2-3 mm in length and of slightly yellowish color. All crystals were clear and transparent. Although the crystals were in general doubly terminated, readings were made only upon the faces of the prism zone, the end faces being extremely small and, hence, difficult of adjustment. The images obtained were very good, considering the size of the crystals. ’
