Illustration of a left lung infected with tuberculosis. Tuberculosis (TB) is a bacterial infection that usually affects the lungs but can affect other body tissues. It causes inflammation and scarring in the lungs, leading to tissue damage. Here, the lower potion of the lung shows infiltration with a gelatinous substance (beige-grey). The centre contains a large abscess and the top contains a cavity surrounded by gangrene. The pleura (membrane lining the lungs, right) is thickened and inflamed. Commonly called consumption in the 1800s, TB was a widespread cause of death during this period before the invention of vaccines (1921) and antibiotics (1943). Published in 'Illustrations of pulmonary consumption' by Samuel George Morton in 1834.