Pyrogallol Photography

                                                                      Carl Wilhelm Scheele

Gallic Acid

Gallic Acid To Pyrogallol

Pyrogallol was first synthesized in 1786 by Carl Wilhelm Scheele, a pioneering Swedish chemist

Scheele obtained pyrogallol by heating gallic acid, a compound extracted from oak galls (plant growths rich in tannins), hence the name “pyro” (heat) + “gallol” (from gallic acid).

Pyrogallol (1,2,3-trihydroxybenzene) readily absorbs oxygen from air when in alkaline solution (typically with sodium hydroxide, NaOH).

In the mid-1800s, scientists discovered that alkaline pyrogallol absorbs oxygen from air, turning brown or black.

                   Pyrogallol: Black And White Photography

Around the 1880s, pyrogallol became an important developer in black-and-white photography. It reduced exposed silver halide crystals to metallic silver, forming the image.

• Used by notable photographers like Edward Weston and Ansel Adams.

• Provided high-contrast and sharp grain structure.

Snapshot 

Pyrogallol was introduced as a photographic developer in the late 19th century, following its earlier use in chemistry and medicine. Its powerful reducing properties and unique image characteristics made it a significant advancement in photographic processing.