Prussian Blue

Prussian blue

Prussian blue (also known as Berlin blue, Brandenburg blue, Parisian and Paris blue) is a dark blue pigment produced by oxidation of ferrous ferrocyanide salts. It has the chemical formula Fe4[Fe(CN)6]3. It consists of Fe3+ cations, where iron is in the oxidation state of +3, and [Fe(CN)6]4− anions, where iron is in the oxidation state of +2, so, the other name of this salt is iron(III) hexacyanoferrate(II). Turnbull's blue is essentially identical chemically, excepting that it has different impurities and particle sizes—because it is made from different reagents—and thus it has a slightly different color.

Prussian blue (medical use)

Prussian blue, also known as potassium ferric hexacyanoferrate, is used as a medication to treat thallium poisoning or radioactive caesium poisoning. For thallium it may be used in addition to gastric lavage, activated charcoal, forced diuresis, and hemodialysis. It is given by mouth or nasogastric tube. Prussian blue is also used in the urine to test for G6PD deficiency.

Prussia

Prussia was a German state centred on the North European Plain. It originated from the 1525 secularization act of the Prussian part of the State of the Teutonic Order. For centuries, the House of Hohenzollern ruled Prussia, expanding its size with the Prussian Army. Prussia, with its capital at Königsberg and then, when it became the Kingdom of Prussia in 1701, Berlin, decisively shaped the history of Germany. Prussia formed the German Empire when it united the German states in 1871. It was de facto dissolved by an emergency decree transferring powers of the Prussian government to German Chancellor Franz von Papen in 1932 and de jure by an Allied decree in 1947.

Blue

Blue is one of the three primary colours in the RGB (additive) colour model, as well as in the RYB colour model. It lies between violet and cyan on the spectrum of visible light. The term blue generally describes colours perceived by humans observing light with a dominant wavelength between approximately 450 and 495 nanometres. The clear daytime sky and the deep sea appear blue because of an optical effect known as Rayleigh scattering. An optical effect called the Tyndall effect explains blue eyes. Distant objects appear more blue because of another optical effect called aerial perspective.

blue

Adjective

1. Of a blue hue.
2. Depressed, melancholic, sad.

Noun

1. The colour of the clear sky or the deep sea; the colour midway between green and violet in the visible spectrum and one of the primary additive colours.
2. Anything coloured blue, especially to distinguish it from similar objects differing only in colour.