Frog's foot mounted in glass box, prepared by Joseph Lister for microscopical examination, September 1857, as part of an experiment researching inflammation.

This specimen was prepared by Joseph Lister (1827-1912) while studying inflammation in the 1850s. Inflammation is the response of tissues in the body to infection or injury. The symptoms are pain, heat, swelling and redness. Lister was not certain that the early stages of inflammation had been correctly understood. He studied a live frog’s leg under the microscope, applying different irritants to the leg such as chloroform and mustard to study how inflammation happened and affected a healthy limb, its blood-vessels and the flow of blood.