22 
Explanation of Plate VII. 
Polished and etched section, of Skookum iron — 'magnified 10 diameters. 
The dark mass in the centre is a small troilite nodule. Partiallyenclosing 
this nodule on the lower side may be observed the outline of a shield of a white 
unknown mineral. Radiating irregularly from the nodule are cooling cracks 
in the iron itself. 
