The old therapies such as bloodletting continued to be popular during the nineteenth century, even though doctors were changing their minds about the cause of disease. Cupping aimed to draw poisonous substances from the body and was popular from Roman times until the late nineteenth century. The glass cup was heated with a flame and pressed on the skin. As the oxygen in the cup was used up a partial vacuum was created powerfully sucking the cup to the body. Dry cupping was performed on unbroken skin creating blisters which were then drained. Wet cupping covered a wound or deliberate incision, and drew out blood, pus and other fluids. This set was made by S. Maw and Son, London.