31. The form of Prussian blue required for the treatment of humans or animals is a special grade. 32. The form of prussian blue required for the treatment of humans or animals is a special grade. 33. First known was to use Prussian blue , which is a solid ion exchange material, which absorbs thallium. 34. Prussian blue helps the body excrete caesium-137.35. It was Duke University's official color from the 1880s until 1961, when the school adopted Prussian blue . 36. Prussian blue is widely used by tool makers when the stamping tools and pressure die casting tools.37. How about burnt sienna and Prussian blue ? 38. Prussian blue lent its name to prussic acid ( hydrogen cyanide ), which was derived from it.39. The form of prussian blue required for the treatment of animals, including humans is a special grade. 40. The caesium is broken away from soil particles and then precipitated with ferric ferricyanide ( Prussian blue ).