Description
Chemical retort

A retort is a piece of apparatus used to heat substances taking part in a chemical reaction. This retort dates from the 18th or early 19th century, but similar apparatus is still an essential part of the modern chemistry laboratory.

Heat was the basic and most powerful way to bring about chemical changes, and hence the retort had to be resistant to high temperatures. Early glassware was less durable and resistant to temperature change than modern varieties, so although some retorts were made of glass, many were made from copper or ceramic, such as this one. This example is made of stoneware, a type of ceramic that will withstand very high temperatures.

Retorts were useful for high temperature distillations, particularly for dry materials. In modern labs, the pieces of apparatus are attached using ground-glass joints to provide a good seal. However, chemists of the eighteenth century would have sealed the retort to another vessel with 'lute' - a mixture often containing dung, clay and egg whites. This was followed by wrapping the joint in cloths dipped in wax or egg white and leaving it to dry. There was no rubber tubing in the eighteenth century; flexible tubes to connect vessels together had to be fashioned from leather, or else were made from glass or earthenware.

15/12/2004
Created by: Ruth Horry on 15/12/2004