36 



MR. E. W. BINNEY ON THE ACTION OF 



described, but the facings of steel were quite free from 

 injury. 



All the wrought iron specimens appear as if they had 

 merely been oxidized, and not converted into plumbago like 

 those of cast iron. This, Hatchett and Becquerel contended, 

 was the case with wrought iron immersed a long time in 

 sea water, and which has been previously alluded to in this 

 paper. 



Mr. Ray informs me that neither the wrought nor cast 

 irons heated on first being taken out of the pit and exposed 

 to the air. 



Unfortunately no analysis was made of the waters, either 

 at the time of their first breaking into the shaft, or when 

 they were nearly drained out of the mine. These would in 

 all probability be of two descriptions, namely, a small supply 

 of salt water found at the bottom of the mine, containing 

 the chlorides of sodium, magnesium, calcium, and other salts 

 usually found in deep collieries, and the vast body of water 

 which burst into the shaft from the old workings of the four 

 feet mine, extending on the level of the coal four or five 

 miles, where the water had been pent up some years, and, 

 like all such waters, containing an abundance of sulphate 

 of iron and some free sulphuric acid, derived from the de- 

 composition of bisulphide of iron, together with silica and 

 carbonic acid. The pressure of the column of water in the 

 shaft would cause the waters below to be charged with highly 

 condensed air, light carburetted hydrogen, and carbonic acid 

 gases. "Waters highly condensed with the latter, both take 

 up considerable amounts of silica, and are known to exercise 

 a destructive action upon iron. 



The eifect of lime in preserving steel and iron from oxy- 



dizing, has been long known and employed by artizans in 



preserving their tools bright. M. Payen* has presented 



several memoirs to the Academy of Sciences, on the subject 



♦ Comptes Rendus, Feb. 1837, No. VI. 



