The present invention relates to a condenser for condensing gasses. The condenser comprises: an inner tube (1) having a bore (3) therethrough; an outer tube (2) having a bore (8) therethrough and two ends, the inner tube (1) passing through the bore of the outer tube (2); and a seal (15, 16) at each end of the outer tube. The outer tube has exterior and interior fins and is sealed to the inner tube so as to define a sealed space (11) between the inner tube and the outer tube. The space (11) is adapted to contain a liquid in contact with the inner tube (1) and the outer tube (2). The invention further relates to a method of condensing a gas using the condenser, a process of making a chemical using the condenser and a kit adapted to be assembled into the condenser.