1,024,510. Purifying smoke. ESSO STANDARD S.A. FRANCAISE. May 27, 1963 [June 19, 1962], No. 21152/63. Heading B1R. In a method of purifying smoke the smoke is contacted with a surface having flowing therein a film of a bitumen or bitumen cut-back which is liquid at the temperature of operation. The contact surfaces may comprise plates arranged in a vertical column and downwardly inclined or in a horizontal column and inclined to the vertical, the smoke traversing a tortuous passage in contact with the flowing films of bitumen or bitumen cut-back. As shown in Fig. 2 the contact surfaces comprise vertical plates 7 arranged in an annular contact zone. In other forms of apparatus suitable for carrying out the method the bitumen or bitumen cut-back flows over a spiral surface arranged in a vertical or a horizontal casing.