Rhodomenia palmata [= Rhodymenia palmata] c. 1843 - 1853

Anna Atkins made this photogram of *Rhodomenia palmata* using cyanotype, a process that yields a distinctive Prussian blue print. This was a relatively new technology at the time, invented in 1842, and Atkins was one of the first to use it, publishing a book of cyanotype impressions of British algae in 1843. Look closely, and you can see the delicate fronds of the seaweed captured in white against the deep blue background. The cyanotype process involves coating paper with a light-sensitive iron salt solution, placing an object – in this case, seaweed – on the paper, and exposing it to sunlight. The areas covered by the seaweed remain white, while the exposed areas turn blue. The final result is a ghostly, ethereal image that captures the delicate structure of the seaweed. Atkins' work sits at the intersection of science and art. She used photography as a tool for scientific documentation, but her images are also beautiful works of art in their own right. She elevated both photography and botanical illustration to a fine art.