· Doctors also made advances. One made drawings that showed the different parts of the human body. Another learned how the heart pumped blood through the body. In the late 1700s, Edward Jenner first used the process called vaccination to prevent disease. By giving a person the germs from a cattle disease called cowpox, he helped that person avoid getting the more serious human disease of smallpox. Scientists made advances in chemistry as well. One challenged the old idea that things were made of only four elements—earth, air, fire, and water. He and other scientists were able to separate oxygen from air.
