134 Mineralogy and Geology of a part of Nova Scotia. 
low the surface of the water, and running down beneath the 
waves, is left exposed only by remarkably low tides. This 
tr: composed 
tuff is a breccia of angular and irregularly 
cupied by irregular masses of native copper, which generally 
are indented by the surrounding matrix. 
arborescent, and never distinctly crystallized. Where expo- 
sed to the action of the waves, the copper is always bright, 
and may be seen for some distance beneath the water ; but, 
