232.    ---------------. [ BERTHELOT, C.] [High-grade Fuels and Lubricants for Internal-Combustion Engines.]  Chim. et Ind., vol. 37, 1937, pp. 1043-1055; British Chem. Abs., 1937, B, p. 869.

                  Specifications for various grades of petrol are discussed.  Aviation spirit for use at high altitudes should have high octane number and relatively close distillation range.  Gum formation is also a greater hazard than in automobile use and this constitutes a difficulty for petrols prepared by the Fischer process or from shale oil.  Lubrication requires an oil stable at 150°.  Specifications for lubricants are discussed and the advantages of refining with solvents are pointed out.  Satisfactory synthetic lubricants can be produced by hydrogenation or by AlCl₃ treatment of oils produced by the Fischer synthesis; chlorination of this material and condensation with an aromatic hydrocarbon gives Paraflow, which depresses the setting point of paraffin lubricants.