As the syrup is heated, it boils and the sugar concentration increases as water evaporates. Individual boils clustered together are called carbuncles. He was covered with painful, pus-filled boils and possibly suffered from gout. Like all liquids, water boils when its vapor pressure reaches its surrounding pressure. It melts at , boils at and sublimes easily. Common ailments included scabies, boils, and eye diseases. Evaporation takes place in the tank where refrigeration occurs as the liquid fuel boils. And frankly, it boils down to a moral issue. Its defining characteristic boils down to just how generic and stale the whole thing is. Ethanol boils at while water boils at . This water then boils and the cycle repeats. At a vacuum water boils at a lower temperature. Fahrenheit soon after observed that water boils at about 212 degrees using this scale. It all boils down to personal choice. Pure water boils at at earth's standard atmospheric pressure.