They are simply dry, boring people who do not understand what living is really all about. He mentions how wedges rust in soggy wood. The people of Seventh Street simply cannot mesh with those who support Prohibition. Toomer says the the wood should be cut and split and allowed to dry in the sun and blow away. It seems as though Toomer is trying to show a conflict between the blacks and the whites at a deeper level.
Wedges are brilliant in the sun.
Seventh Street is described as a wedge of nigger life breathing its loafer air. Therefore, he is saying that if the whites are allowed to continue looking down on blacks because they are trying to merge into and become part of white society, they will decay and be broken down by their efforts. However, if the wood is chopped up and the whites pride is broken down and dried up, then the blacks will be brilliant in the sun. The blacks are crying out for freedom from oppression and the symbol of their black reddish blood flowing through the streets and around the corners and into Washington is extremely obvious as a symbol of their cry. Blood suckers of the War would spin in a frenzy of dizziness if they drank your blood.