F1GUUES OF CRYSTALS, 



429 



Fig. 385. 



Having thus produced the planes d^ c, and e, we 

 rnay add the planes />, and b*, by tracing No. 3, 

 fig. 384, .on a separate paper, as No. 5, fig. 385, and 

 above it draw an entire primary form, as shewn by 

 No. 4. 



To place the planes hi and * on the figure, we 

 require their intersections with <?, P, and M, and 

 with each other. 



