Accordingly my improved process for manufacturing lithopone consists, in its preferred form, of bringing about in a single reaction the production and precipitation from an Serial No. 37,236. (No specimens.)

sufiicient sulphuric acid to extract up to 95 per cent or more, of the titanium oxide prescut. This extraction is carried on so that the resulting product, after the addition of the required amount of sulphuric acid, is in the form of a dry powdered .mass, in which approximately 95 per cent of the titanium is in a soluble form. Th dry powdered mass is thenextractedin suitable leaching tanks with water, whereby a solution of approximately 70 grams of sulphuric acid and 100 grams of titanium oxide to the liter, is obtained.