A variety of shades, of great beauty, and considerable permanence, may also be given by the prussian-blue process.
Indigo is not discharged by sodium hydroxid, while prussian-blue is.
"Nothing whatever to do with the Army," he snapped, and a prussian-blue opponent was smacked off into an arid and hoopless waste.
Prussian blue Prus·sian blue (prŭsh'ən)
See Berlin blue.