The paper by J. E. Hirsch proposes the concept of a "spin Hall effect" in paramagnetic metals, where a transverse spin imbalance is generated when a charge current circulates, leading to a "spin Hall voltage." Conversely, a transverse charge imbalance is generated when a spin current circulates in the absence of charge current and magnetic field. The author suggests an experiment to generate and detect this spin current in a paramagnetic metal. The paper discusses the spontaneous or anomalous Hall effect in ferromagnetic metals, where the Hall resistivity is influenced by the applied magnetic field and magnetization. These effects are attributed to various mechanisms, including skew scattering by impurities and phonons, and the "side jump" mechanism. The author argues that the existence of these effects in ferromagnetic metals provides experimental proof that electrons with spin experience a transverse force when moving in a longitudinal electric field. In the case of paramagnetic metals or doped semiconductors, the author proposes that skew scattering mechanisms will scatter electrons with spin up preferentially in one direction and spin down electrons in the opposite direction, leading to a spin imbalance. This imbalance, rather than a charge imbalance, will result in a spin Hall voltage. The paper outlines a method to detect this spin Hall voltage by measuring the difference in magnetization at the edges of a sample when it is connected to a transverse metal strip. The spin current generated by the spin imbalance will cause a transverse voltage that can be measured with a voltmeter. The author provides detailed calculations for the magnitude of the spin Hall voltage and the conditions under which the experiment can be conducted successfully. The paper concludes by discussing the potential practical applications of this experiment in spin electronics and the possibility of extending the study to two-dimensional systems.The paper by J. E. Hirsch proposes the concept of a "spin Hall effect" in paramagnetic metals, where a transverse spin imbalance is generated when a charge current circulates, leading to a "spin Hall voltage." Conversely, a transverse charge imbalance is generated when a spin current circulates in the absence of charge current and magnetic field. The author suggests an experiment to generate and detect this spin current in a paramagnetic metal. The paper discusses the spontaneous or anomalous Hall effect in ferromagnetic metals, where the Hall resistivity is influenced by the applied magnetic field and magnetization. These effects are attributed to various mechanisms, including skew scattering by impurities and phonons, and the "side jump" mechanism. The author argues that the existence of these effects in ferromagnetic metals provides experimental proof that electrons with spin experience a transverse force when moving in a longitudinal electric field. In the case of paramagnetic metals or doped semiconductors, the author proposes that skew scattering mechanisms will scatter electrons with spin up preferentially in one direction and spin down electrons in the opposite direction, leading to a spin imbalance. This imbalance, rather than a charge imbalance, will result in a spin Hall voltage. The paper outlines a method to detect this spin Hall voltage by measuring the difference in magnetization at the edges of a sample when it is connected to a transverse metal strip. The spin current generated by the spin imbalance will cause a transverse voltage that can be measured with a voltmeter. The author provides detailed calculations for the magnitude of the spin Hall voltage and the conditions under which the experiment can be conducted successfully. The paper concludes by discussing the potential practical applications of this experiment in spin electronics and the possibility of extending the study to two-dimensional systems.