/y/v2 Tnw^ MDCCCLVir j(Xril. 
^ S. Ssi 
A. .GROUPS OF CRYSTALS OF EXCR.E TINE SEEN WITH THE NAKED EYE. 
H.&Q.GIIOUPS OP CRYSTALS OF EXCRETINE SEEN UNDER DIFFERENT MAGNIFYINO POWERS. 
J.lasire, Uth^. 
