Abstract
THE production of a fibrosis due to inhalation of haematite in man has already been disucssed by Goadby (1925). The following experiments were made to see what effects were produced by exposing guinea-pigs to the dusts of (a) haematite (Fe2O3) and (b) levigated iron.Finacial assistance towards these experiments was very kindly rendered by the Mines Department, to the Inspectors of which I am also indebted for the haematite powder from Cumberland.