Sub-Product

During Coal Tar Distillation the First Fraction is taken as “First Runnings,” up to a temperature of 105°C in the Still, and a Second Fraction as “Light Oil,” up to 210°C, but more usually these two are not separated in the First Distillation, and the First or “Light Oil” Fraction then embraces everything which comes over until the drops no longer float on, but show the same specific gravity as Water. The specific gravity of this fraction varies from 0.91 to 0.94.