This week we have cyanotypes, one of the earliest forms of photography dating back to the 1840s. The botanist Anna Atkins (1799-1871) is credited with being the first person to publish a book illustrated with photographs - in this case cyanotypes - as opposed to the more traditional engravings or woodcuts. Her book Photographs of British Algae: Cyanotype Impressions (1843), was a milestone in botanical illustration, and today the delicate beauty of her images of algae, flowers, ferns, and leaves is also widely admired.