In April 1721, residents of Boston, Massachusetts, suffered an outbreak of smallpox. The disease was feared because it had a high mortality rate and left most survivors terribly scarred. In response to the epidemic, a Boston clergyman, Benjamin Colman, wrote a pamphlet titled Some Observations on Receiving the SMALL-POX by Ingrafting or Inoculating. He wrote at a time when there were few trained doctors and when clergyman, likely the most highly educated men in their communities, tended to be deeply involved in medical care. His pamphlet presented his observations on a new way of attacking smallpox: inoculation. The technique, often called variolation, involved using pus from the sores of an infected person to give another person a mild case of the disease and thus lifetime immunity to it.