Prussian Blue – The Traditional Blue of Blueprints: Its Chemistry?
[caption id="attachment_24391" align="alignright" width="480"] A Canadian architectural blueprint. Image by Chris Gonzaga.[/caption] The image you see at right is a traditional architectural blueprint. In fact, this style of blue-inked drawing is how the word blueprint originated. Now the chemistry of this blue colored “ink” is of interest, both historically, and from the science perspective. Let’s see how. Identifying the Blueprint Ink The blue ink has a number of names including Paris Blue and Berlin Blue. But the name it is best known by historically is Prussian Blue. Perhaps you will note Prussian Blue is similar to another name, Prussic Acid. Prussic Acid is another name for the deadly poisonous hydrogen cyanide, HCN. And in fact, the ink is closely connected to this acid. But which was first to be called…