British Association, SOtJi Report, Sheffield, 1910.] 



No. 3. 

 Iron-Carbon-Sulphur Alloy (4-37 per cent. Carbon). 



[Plate IX. 



While thick bands = massive carbide of iron. 

 ( 'oniplex structure = iron — iron-oarbide-sulphide-pearlite eutectio. 



No. 4. 

 Same as No. 2, heat-tinted and more highly magnified. 



Broad bands =niassive carbide of iron with inclusion of sulphide of iron. 



Complex structure— jointed euteetic of Fe— Fe 3 C— FeS. 



The white specks are all FeS. 



