Boil, a disease called by medical men furunculus. It is a phlegmonous tumor, which rises externally, attended with redness and pain, and sometimes with a violent, burning heat. Ultimately it becomes pointed, breaks, and emits pus. A substance called the core is next revealed. It is purulent, but so thick and tenacious that it looks solid, and may be drawn out in the form of a cylinder, more pus following. The boil then heals. A blind boil is one which does not suppurate.
Entry from Everybody's Cyclopedia, 1912.