A scaling law in the hydrodynamics of anisotropic viscous liquids

Summary We show that 1) the stationary flow of an isotropic liquid in a given viscosimeter is described by the same equations valid for a wellaligned nematic liquid crystal, having suitable values of the five viscosity coefficients, flowing in a viscosimeter like the previous one, but whose dimensions along the average molecular directionň are contracted; 2) a similar equivalence exists for a nematic flowing in a suitably chosen viscosimeter in two experiments which differ only for the direction ofň. This equivalence allows us to exactly compensate boundary effects in the measurement of the ratio between two of the Miesowicz viscosity coefficients. Furtherly a new particularly simple derivation of the Rayleigh dissipation function for nematics is given. To speed up publication, the author of this paper has agreed to not receive the proofs for correction.