IRON EATEN

Evening Star, Issue 22576, 18 February 1937, Page 7

IRON EATEN

THE WORK OF BACTERIA Bacteria, aided only by moisture and such chemicals as are found in ina J]y soils, can eat through the most solid of iron pipes, acccording to_ experts at the Chemical Research Station at Teddington, under the Department of Scientific and Industrial Research, says ‘ The Morning Post.’ Research on the ways of these bacteria, a representative of ‘ The Morning Post ’ was informed, has solved the mystery of how iron and other metals can become corroded in the absence of oxygen. , , The bacteria are members ot an interesting and versatile family. One strain, which best flourishes at about blood temperature, was first discovered in an ice-covered ditch, and they can multiply and prosper under the most widely varying chemical conditions. Their speciality is the transformation of the type of chemical salts known as “ sulphates ” into the gas “ hydrogen sulphide,” which provides the smell of bad eggs. Owing to this proclivity, their activities at the base of commmercial gas-holders are already known to have given trouble. Gas companies dislike the idea of their gas being con-taminated-even by hard-working bacteria. As regards corrosion, the essential crime of these bacteria is that, instead of breathing in oxygen, they breathe it out'. This is a necessary result of the chemical transformation already mentioned*

Their activity is reflected in the steady corrosion of cast-iron pipes in their vicinity, rusting proceeding from the outside of the pipe _ inwards. As a result the carbon originally contained in the cast iron is left behind as a soft layer, the iron itself being gradually eaten away. It is considered probable that this same type of corrosion may also be produced in other metals.