Measurements have been made of the morphology and optical properties of soot produced by the combustion, in the laboratory, of petrol, diesel, fuel oil, paraffin, butane and wood in still air. The specific extinction coefficients of all the hydrocarbons fall in the range 9.1-11.6 m(2) g(-1), whilst that for wood was found to be 7.8 m(2) g(-1). The results indicate that the soots, except that from wood, are fractal-like. Electro-optical scattering was used to study the nonsphericity of the various smokes. These measurements agree with textural and density fractal analysis. Electro-optical scattering and fractal analysis are both excellent indicators of particle morphology.