Galvanic corrosiveness of soil waters

Results are presented of a study of the relation of pH of soil waters to galvanic action between couples of lead, copper, iron, and carbon. Galvanic-cell tests were made using as electrolytes actual soil waters or soil extracts from 31 locations at which trouble had been experienced. The following conclusions apparently can be drawn from this investigation: 1. Galvanic corrosiveness on lead, copper, and iron appears generally more severe for soil waters of low pH than for those of high pH. 2. Indications are that the static potentials of lead and iron are practically constant in soil electrolytes of pH up to approximately ten; as pH is increased above ten, lead becomes more negative and iron more positive. The potential of copper becomes more negative in substantially straight-line relation with increasing pH. Carbon potentials appear to be practically independent of pH of soil waters. 3. For electrodes of lead, copper, iron, and carbon in soil waters, the relation of degree of polarization to pH of electrolyte seems to show definite trends.