When inorganic chemists were king

Ahhh … the glory days. We all have idealized thoughts of those perfect places and times. Eras where we wish we had lived. Eras we currently wished were our actual present. Conservatives want it to be 1950 again, Tea Partiers would rather it be 1800 and Democrats yearn for the long ago days of 2008. For inorganic chemists, that time corresponded to the Age of Impressionism, roughly to the 19th century.

Inorganic chemistry deals with making and studying chemicals that have metals in them. Well … that’s the generic definition, and the one we’ll use here. Computer chips (silicon), vitamin B12 (cobalt) and blue ray lasers (indium gallium) are a very small set of examples of inorganic materials. While inorganic chemists play a substantial role with driving modern technology, they had a heyday during the Age of Impressionism where their work was at its most visible.

During the 1800s, chemists got to be very good at developing new pigments. These pigments were valuable for their use in textiles and other industrially produced items. (When it was founded BASF was a company whose main purpose was to produce dyes.) The dyes that inorganic chemists made were longer lasting (i.e. they didn’t fade as quickly) than dyes extracted from natural sources. These dyes ultimately found prominent places in the palettes of the Impressionist painters.

Bathing at La Grenouillère, Claude Monet.

Prussian blue might have been the first synthetic inorganic dye to find prominence in paintings. The dark blue colors in Monet’s Bathing at La Grenouillère come from Prussian blue. The chemical name for Prussian blue is ferri ferrocyanide. All that means is that it is made up of cyanide (yup … that kind of cyanide – though cyanide in this form isn’t toxic) bound to some iron atoms. (Prussian Blue is also the featured pigment in Hokusai’s The Great Wave off Kanagawa)

Vase with Twelve Sunflowers, Vincent van Gogh.

Chrome Yellow features prominently in the Sunflower paintings by van Gogh. Chrome Yellow (lead chromate) was one of the original lead paints and has more recently been replaced by Cadmium Yellow.

Bathers by a River, Henri Matisse.

A concentrated version of Cadmium Yellow (cadmium sulfide) is used to produce the red color in Matisse’s Bathers by a River. Cadmium sulfide is also a semiconductor and is used in many electronic devices to detect light.

Green Apples, Paul Cezanne.

The green pigment Paris Green (copper(II) acetoarsenite) was unequaled among other green pigments because it was so resistant to fading. Unfortunately it was also unequaled in its ability to poison those who used it. Cezanne’s diabetes was likely caused by arsenic poisoning brought on by continued use of this pigment. Monet’s blindness and van Gogh’s cutting-his-ear-off-craziness could also be due to the toxic effects of the arsenic and lead based-paints that were so prevalent in their time.

So, the next time you’re at the art museum, make sure you take time to enjoy all of the inorganic chemistry you are looking at! (If you want to read more about chemistry and art Sam Kean, author of the awesome book – The Disappearing Spoon – has written a really cool series of articles for NPR’s Science Friday website.)

-mrh