Published methods for the determination of total sulphur in soil are reviewed. A method is described for determining total sulphur in soil in which all the sulphur is reduced to sulphide by heating the soil with ferrum reductum. The sulphide is treated with acid and the evolved hydrogen sulphide estimated iodimetrically with standard alkaline hypochlorite solution as absorbent. The method is specific for sulphur. It has been found applicable to the determination of sulphur in soils of widely diverse origins and in many kinds of pure substances, both organic and inorganic. An error of ± 2.5% can be expected in the determination of total sulphur in soil.