Distillation, or classical distillation, is the process of separating the components or substances from a liquid mixture by using selective boiling and condensation. Dry distillation is the heating of solid materials to produce gaseous products. Early evidence of distillation was found on Akkadian tablets dated c. 1200 BCE describing perfumery operations. The tablets provided textual evidence that an early primitive form of distillation was known to the Babylonians of ancient Mesopotamia.[8] Early evidence of distillation was also found related to alchemists working in Alexandria in Roman Egypt in the 1st century CE.