[Sergeant of the 92nd Gordon Highlanders reading the orders of the day]

The Getty Museum owns both this positive salt print and a paper negative of the same image (see 84.XM.445.3). To make a calotype, Hill and Adamson (David Octavius Hill [1802-70] and Robert Adamson [1821-48]) first coated high-quality writing paper with a solution of silver nitrate. After drying, the paper (they favored the Whatman Turkey Mill brand) they treated it with potassium iodide. Before exposure, they applied a mixture of acetic and gallic acids and silver nitrate. The image caught on the resulting negative was latent, therefore requiring development with additional silver nitrate and acetic and gallic acids. Once this was completed, they placed the negative on top of a second sheet of treated paper, and both were left in direct sunlight. This form of contact printing meant that the print size correlated to that of the negative. Waxing the negative increased its transparency and strengthened the durability of the paper. Many critics likened calotypes to engravings and mezzotints, because the image soaked into the paper fibers, causing a slightly blurred, painterly effect. The marine painter Clarkson Stanfield (1793-1867), upon receiving an album of Hill and Adamson's works in 1845, declared that he "would rather have a set of them than the finest Rembrandts."

The 92nd Gordon Highlanders were stationed at Edinburgh Castle from July 1845 until August 1846. Hill used some of the calotypes of the soldiers as studies for his 1847 painting Edinburgh Old and New (National Gallery of Scotland).

Adapted from Anne M. Lyden. Hill and Adamson, In Focus: Photographs from the J. Paul Getty Museum (Los Angeles: J. Paul Getty Museum, 1999), 26. ©1999, J. Paul Getty Museum.