Dippel, Johann

Prussian Blue is probably the most famous blue pigment. It was discovered by accident in 1704 and is made from potassium ferro-cyanide and ferric chloride. Heinrich Diesbach, a colour manufacturer of Berlin, had run out of potash (potassium carbonate) with which to make a red lake so he borrowed some from Johann Dippel an alchemist. While this worked fine, something happened to the solution after he had filtered off the red lake it turned a deep blue colour. Dip-pel s potash had been made from calcined bones and these contained cyanide from the decomposition of their protein component and the cyanide had reacted to a deep blue compound which we now know as... 

For example, Allen G. Debus, Chemistry and Medical Debate Van Helmont to Boerhaave (Canton, MA Science History Publications, 2001) compare with Karl Hufbauer, The Formation of the German Chemical Community (1720-1795) (Berkeley, CA University of California Press, 1982), 8-11,167-68, and Johanna Geyer-Kordesch, Chemie und Alchemie J. J. Becher, G. E. Stahl, J. S. Carl, und J. C. Dippel, in Johann Joachim Becher (1635-1682), ed. Gotthardt Fruhsorge and Gerhard F. Strasser (Wiesbaden Otto Har-rassowitz, 1993), 127 12. 

Prussian blue was accidentally obtained by Diesbach, a colour manufacturer of Berlin, in 1704, by precipitating an iron solution with an alkali obtained from the alchemist Johann Conrad Dippel which had been used in making Dippel s animal oil (see Vol. Jl, p. 378). It was first described anonymously in 1710 as a non-poisonous pigment suitable for oil colours,... 

Analysis has also uncovered at least one forgery. The date of fabrication of Ms 972 from the University of Chicago Special Collections, familiarly known as the Archaic Mark, had been tentatively attributed to the twelfth century. Analysis showed that an iron blue [42] was ubiquitous in this manuscript, raising doubts about its authenticity. The iron blues are the first of the artificial pigments with a known history and an estabhshed date of first preparation. The color was made by the Berlin color makers Johann Jacob Diesbach and Johann Konrad Dippel (1673-1734) in or around 1706 [44,45]. Moreover, according to Gettens and Stout [31, 32], the material is so complex in composition and mediod of manufacture that there is practically no possibility that it was invented in other times and places. This fact, in addition to other evidence [46]—radiocarbon dating of the parchment... 

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