Which preposition to use with opacity

of Occurrences 4%

Nothing is so impressive in the mighty convulsion which ensued as the mental opacity of the privileged orders, which caused them to increase their pressure in proportion as resistance increased, until finally those who were destined to replace them reorganized the courts, that they might have an instrument wherewith to slaughter a whole race down to the women and children.

out Occurrences 1%

Nature makes the poet, not by adding to, but by taking from; she takes all blur and opacity out of him; condenses, intensifies; lifts his nerves nearer the surface, sharpens his senses, and brings his whole organization to an edge.

Which preposition to use with  opacity